Birthday Present

Math Forum: Ask Dr. Math FAQ: The Birthday Problem -- Ask Dr. Math: FAQ The Birthday Problem Dr. Math FAQ || Classic Problems || Formulas || Search Dr. Math || Dr. Math Home Suppose you flip a coin and bet that it will come up tails. Since you are equally likely to get heads or tails, the probability of tails is 50%. This means that if you try this bet often, you should win about half the time. What if somebody offered to bet that at least two people in your math class had the same birthday? Would you take the bet? This question is more complicated than flipping a coin, because the chance of finding two people with the same birthday depends on the number of people you ask. If there were only one other person in your math class, you might be surprised to find out that she had the same birthday as you. If there were a pair of people with the same birthday in a class of 366 people, would you still be surprised? How large must a class be to make the probability of finding two people with the same birthday at least 50%? Let's forget about leap year when we solve this problem (no February 29 birthdays!) This way, we can assume that a year is always 365 days long. We'll start by figuring out the probability that two people have the same birthday. The first person can have any birthday. That gives him 365 possible birthdays out of 365 days, so the probability of the first person having the "right" birthday is 365/365, or 100%. The chance that the second person has the same birthday is 1/365. To find the probability that both people have this birthday, we have to multiply their separate probabilities. (365/365) * (1/365) = 1/365, or about 0.27%. Now, what about three people ? The chance of the first and second person sharing a birthday is still 1/365. The first and third person might share a birthday instead. The probability of that is 1/365 as well. But what if the second and third person shared a birthday? And what if all three of them had the same birthday? Things are getting complicated fast. Four or five people would be even messier. Is there a simpler way? To solve the birthday problem, we need to use one of the basic rules of probability: the sum of the probability that an event will happen and the probability that the event won't happen is always 1. (In other words, the chance that anything might or might nothappen is always 100%.) If we can work out the probability that no two people will have the same birthday, we can use this rule to find the probability that two people will share a birthday: P(event happens) + P(event doesn't happen) = 1 P(two people share birthday) + P(no two people share birthday) = 1 P(two people share birthday) = 1 - P(no two people share birthday). So, what is the probability that no two people will share a birthday? Again, the first person can have any birthday. The second person's birthday has to be different. There are 364 different days to choose from, so the chance that two people have different birthdays is 364/365. That leaves 363 birthdays out of 365 open for the third person. To find the probability that both the second person and the third person will have different birthdays, we have to multiply: (365/365) * (364/365) * (363/365) = 132 132/133 225, which is about 99.18%. If we want to know the probability that four people will all have different birthdays, we multiply again: (364/365) * (363/365) * (362/365) = 47 831 784/ 48 627 125, or about 98.36%. We can keep on going the same way as long as we want. A formula for the probability that n people have different birthdays is ((365-1)/365) * ((365-2)/365) * ((365-3)/365) * . . . * ((365-n+1)/365). If you know permutation notation, you can write this formula as (365_P_n)/(365^n). That's the same as 365! / ((365-n)! * 365^n). We've made some progress, but we still haven't answered the original question: how large must a class be to make the probability of finding two people with the same birthday at least 50%? We know that the probability of finding at least two people with the same birthday is 1 minus the probability that everybody has a different birthday, and we know how to find the probability that everybody has a different birthday for any number of people. The easiest way to find the right class size is to use a calculator to try different numbers in the formula. It turns out that the smallest class where the chance of finding two people with the same birthday is more than 50% is... a class of 23 people . (The probability is about 50.73%.) From the Dr. Math archives: Probability Theory: Coincidental Birthday Probability of the Same Birthday within a Group Birthday Probabilities Three Share a Birthday The Birthday Problem; Queuing at a Bank Birthday Probability, Class of 25 One Person of Seven Born on Monday Odds of Left-Handedness in a Group From the Web: The Birthday Problem: A short lesson in probability , George Reese A Java applet that you can use to test different class sizes (it works better with small classes) and graphs of the probability for different numbers of people. The Law of Small Errors , Keith Devlin The birthday problem, and related questions - what's the probability that someone will have your birthday? Birthday Surprises, Ivars Peterson Birthday Problem, Eric Weisstein's World of Mathematics Coincidence, Alexander Bogomolny How to Read Mathematics, Shai Simonson and Fernando Gouveau This article uses an explanation of the birthday problem as an example. An Introduction to Mathematica and the "Birthday Problem," Louie Beuschlein For a general review of probability: Probability, Dr. Math FAQ Probability in the Real World, Dr. Math FAQ - Ursula Whitcher, for the Math Forum Submit your ownquestion to Dr. Math [ Privacy Policy ] [ Terms of Use ] Math Forum Home || Math Library || Quick Reference || Math Forum Search Ask Dr. Math ® © 1994-2005 The Math Forum http://mathforum.org/dr.math/

HOUSEWARMING GIFT BASKETS, Free

HOUSEWARMING GIFT BASKETS, Free Shipping, New Home Gifts, Welcome Neighbor, Real Estate Closing Gifts | Gifts $0-50 | Baskets $50-80 | Gifts $80-125 | Luxury Gifts | Gift Shop | Gift Tracking | Gift Shipping | FAQ | Email | How To Buy | Privacy | Friends | Gift Links | Gift Baskets, Adorable Gift Baskets Offers Gourmet Food Gifts, Fresh Fruit Baskets, Fast Mail Order Gift Delivery with Free Ground Shipping and Satisfaction Guaranteed | HOME | Relaxation | New Mom | Birthday | Get Well Gifts | Bath | Same Day Gift Delivery | Thank You | Housewarming | Sympathy | Gardening | Gift Towers | Corporate | | Christmas Holiday Gifts | Men | Women | New Baby | Kids | Gourmet Food Baskets | Snack Baskets | Pasta | Fruit Baskets | Coffee | Tea | Flowers | Picnic | Cookies | | Site Map | Sale | Last Minute Gifts | Breakfast Gifts | Business Gifts | Candles | Movie Gifts | Anniversary | Romantic | Sports Gift Baskets | Care Packages | 1 2 3 Next HOUSEWARMING GIFT BASKETS, Free Shipping, New Home Gifts, Welcome Neighbor, Real Estate Closing Gifts New Home Gift Baskets , Gifts for New Neighbors, Realtor Closing Gifts, Welcome Home Gifts, Unique Housewarming Gift Baskets, Moving Day Care Packages and New Apartment Presents. Send New Home Congratulations, New Apartment Gifts, Welcome Neightbor Gifts, Congratulate Home Owner, Gift Baskets and Presents for Homeowners. Real Estate Professionals , search our extensive selection of real estate agent and client gifts, Realtor closing gifts and housewarming gifts to support, enhance and promote your real estate business. "Super job on my orders. I was looking for something thoughtful, yet appropriate, to send to a couple of colleagues and Adorable Gift Baskets had the perfect gifts. I just couldn't believe how many options I had to choose from. Then selecting an item, placing the order and tracking it was painless. When I followed-up on the delivery of my gift baskets, the level of attention to my inquiry was excellent and refreshing. I could not believe just how fast customer service was able to get me the information I was looking for. While many companies have forgotten what customer service is all about, Adorable certainly has not. Thank you and you will be hearing from me again." - Bill Jackson, Long Island New York more .. New Home Buying Articles: Housewarming Gift Ideas Negotiating A Real Estate Contract Realtors; 3 Reasons Why You Need A Website Our adorable housewarming gifts make great new apartment gifts and are great for saying "Welcome Home" to new residents. These attractive gifts are terrific resident retention gifts and real estate rental marketing tools as well as real estate closing gifts. And, when things don't go exactly as planned, they make really nice apology gifts. No Place Like Home Gift $58.50 HOUSEWARMING GIFT - NG3053 Show them you share the excitement of their new home, condo or apartment with a delightful two story gift box filled with tasty treats... Fancy Food Gift Basket $69.95 Food gifts delivered 810012 Fast gourmet food gift delivery for birthday, get well, thank you, sympathy, new baby and housewarming. Food gifts include gourmet food, snacks, cookies, candy and much more. Moving Day House Warming $63.50 New home gift box A new home gift designed especially for the new home owner. Great housewarming or real estate closing gift. 2 sizes available. 1 2 3 Next SHOP ONLINE AT ADORABLE GIFT BASKETS where online shopping is Secure , hassle free and just plain fun. Add freely to your shopping cart. You are never charged until after you have reviewed and confirmed your gift basket order. Gift baskets are delivered within the continential US. Gift Basket Shipping Options and Approximate Arrival Times. Occasional component substitutions become necessary. Gift basket ideas include thinking of you presents, promotional gifts, thanks, business client appreciation, weddings, mothers, housewarming, sympathy, grandparents presents, husband, boyfriend, Mother, daughter, grandma, kids, clients, weddings, welcome, new home, over hill birthday, romantic, childrens presents, mothers day, bridal and baby showers, promotional, professional, new moms and babies, kids, promotions, special event, parties, celebrations, corporate events, condolence, wedding and bridal showers, bridesmaid, new year, care packages, gift boxes, cookie tins, fathers day, friends and family. Theme gift baskets are celebration gifts for almost any event such as Happy Birthday, New Babies, Thank You, Weddings, Coporate, New Mom, New Dad, Father's Day, Grandparents Day, Administrative Professional, Mother's Day, Thanksgiving, Real Estate Closing, Golf, Football, Fishing, Sports, Basketball, Over The Hill, Valentines Day, Easter, St Patricks Day, Cheer Up, Baby Showers, Retirement, July 4th, Customer Appreciation, Holiday, Christmas, Get Well, Staff Recongition, House Warming, Going Away Party, Anniversaries, Reunions and Special Occasions. I Holiday Gift Baskets I Administrative Gifts I Wedding Gifts I Baby Shower Gifts I Bear Gift Baskets I Care Packages I Relax/Pamper/Spa I Birthday Gifts For Her I I Cookie Grams I Cheesecake I Chocolate Baskets I Coffee Gift Baskets I Condolence Baskets I Cookies Tins I Business Gift Ideas I Easter Baskets I Father's Day I I Florist I Fresh Fruit Gifts / Baskets I Garden Baskets I Get Well Soon I Boxed Gift Sets I New Mothers I Kids / Children I Comfort Gifts I Birthday Gifts For Him I I Food Baskets I New Home Gifts I Italian Food I Mail Order Gifts I Mother's Day I Picnic Gift Baskets I Romance Baskets I Tower Gifts I Golf Baskets I I Fishing Baskets I Sweets / Candy I Tea / Teapot Baskets I Appreciation Baskets I Christmas Gift Shop I Gift Basket Directory I | Arizona Gift Baskets | Arkansas | California Gift Baskets | Colorado | Connecticut Gift Baskets | Delaware Gifts | DC Gifts | Florida | Georgia | Idaho | Illinois | Indiana | Iowa | Kansas | Kentucky | Louisiana | | Maine | Maryland Gift Baskets | Massachusetts | Michigan | Minnesota | Mississippi | Missouri | Montana | Nebraska | North Carolina Gift Baskets | North Dakota | Ohio Gift Baskets | Oklahoma | Oregon | | Pennsylvania Gift Baskets | Rhode Island | South Carolina Gift Baskets | South Dakota | Tennessee Gift Baskets | Texas | Utah | Vermont | Virginia Baskets | Washington Gift Baskets | West Virginia | | Wisconsin Gift Baskets | Nevada Gift Baskets | New Hampshire Gift Baskets | New Jersey Gift Baskets | New Mexico Gift Baskets | New York Gift Baskets | Wyoming Gifts | Search All Gift Baskets |

Gift Certificates | Gift

Amazon.com: Gifts Your Store Gifts See All 31 Product Categories   Your Account | Cart | Wish List | Help Wedding Registry | Baby Registry | Top Sellers | Gift Certificates | Gift Services | Wish List | Free E-cards Search Amazon.com Books Popular Music Music Downloads Classical Music DVD VHS Apparel Yellow Pages Restaurants Movie Showtimes Toys Baby Computers Video Games Electronics Camera & Photo Software Tools & Hardware Office Products Magazines Sporting Goods Outdoor Living Kitchen Jewelry & Watches Gourmet Food Beta Beauty Beta Musical Instruments Health/Personal Care Travel Cell Phones & Service Outlet Auctions zShops Everything Else Scientific Supplies Medical Supplies Indust. Supplies Car Parts Home Furnishings Lifestyle Pet Toys Arts & Hobbies Web Search WISH LISTS Looking for the perfect gift for someone? See if they have a Wish List.Enter name or e-mail address: BROWSE Apparel Beauty Books Camera & Photo Computer & Video Games Computers DVD Electronics Flowers Gourmet Health & Personal Care Home & Garden Jewelry & Watches Kitchen & Housewares Magazines Music Musical Instruments Outdoor Living Software Sports & Outdoors Tools & Hardware Toys for Boys Toys for Girls Video Stumped when it comes to finding the perfect gift? We're hereto help. The products below are some of our favorites, and we hope thespecial people on your list will enjoy them as much as we do. Most Wished For | Most Gifted | Top Rated by Customers Gifts Under $25 Real Simple [Magazine Subscription] Price: $28.68 All gifts under $25 Gifts Under $50 Seinfeld - Seasons 1 & 2 Price: $32.47 All Gifts Under $50 Gift Certificates Amazon.com Gift Certificate Price: $5.00 - $5,000.00 All Gift Certificate Options For Him The Complete Peanuts 1950-1954 Boxed Set [Box set] Price: $32.97 All Gifts for Him For Her The No. 1 Ladies Detective Agency Box Set: "The No. 1 Ladies Detective Agency" "Tears of the Giraffe" "Morality for Beautiful Girls" [Box set] Price: $23.66 All Gifts for Her For Kids Shrek 2 (Widescreen Edition) Price: $17.99 All Gifts for Kids Top Sellers in Toys & Games Cranium Hullabaloo Game Price: $19.99 All Top Sellers in Toys & Games Top Sellers in Books Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation Price: $12.94 All Top Sellers in Books Top Sellers in Gourmet Food 6-Star All Occasion Basket - Harry and David Price: $59.95 All Top Sellers in Gourmet Food Early Adopter Picks in Electronics PalmOne Tungsten T5 Handheld [CD] Price: $330.74 More Early Adopter Picks in Electronics Best Books of 2004 Dress Your Family in Corduroy and Denim Price: $15.72 More of the Best Books of 2004 Early Adopter Picks in Tools Black & Decker BDL110S BullsEye Laser Level Stud Sensor Price: $39.96 More Early Adopter Picks in Tools Where's My Stuff? • Track your recent orders . • View or change your orders in Your Account . Shipping & Returns • See our shipping rates & policies . • Return an item (here's our Returns Policy ). Need Help? • Forgot your password? Click here . • Redeem or buy a gift certificate. • Visit our Help department . Search All Products Books Popular Music Music Downloads Classical Music DVD VHS Apparel Yellow Pages Restaurants Movie Showtimes Toys Baby Computers Video Games Electronics Camera & Photo Software Tools & Hardware Office Products Magazines Sports & Outdoors Outdoor Living Kitchen Jewelry & Watches Beauty Gourmet Food Beta Musical Instruments Health/Personal Care Pet Supplies Travel Books Cell Phones & Service Outlet Auctions zShops Everything Else Scientific Supplies Medical Supplies Indust. Supplies Automotive Home Furnishings Lifestyle Arts & Hobbies for Turn your past purchases into $$$ Learn more about selling at Amazon.com today! Top of Page Amazon.com Home | Directory of All Stores Our International Sites: Canada | United Kingdom | Germany | Japan | France  | China Contact Us | Help | Shopping Cart | Your Account | Sell Items | 1-Click Settings Investor Relations | Press Releases | Careers Conditions of Use | Privacy Notice © 1995-2005, Amazon.com, Inc. or its affiliates

Buy Gift Card and

Best Buy GC - $50 Gift Card - GAMERS JC ');}else {document.write('');}//-- Entire Site Electronics Cameras & Camcorders Computers Home Appliances Phones & Communications Office Products Music -Album Title -Artist -Song Movies -Title -Person Games Software Resources Birthday Best Buy Geek Squad Weddings Music Games Movies Purse Best Buy Global Gift Cards Product Info Our Price: $50.00 Free Shipping In Stock Usually ships in 1 business day Estimate arrival time . Store Availability Not Available Best Buy GC$50 Gift Card Model: GAMERS JC So many games, so many systems. Where to start? Give a Best Buy Gift Card and let the gamers in your life decide themselves. Our gaming-themed Gift Cards are shipped free of charge, good toward any future in-store and online purchase. More Options Compare with products in this price range. About Us News Center Careers For Our Investors Business to Business Community Relations Store Pickup Returns & Exchanges Store Locator Weekly Ad Financing Offers Buy Gift Cards Check Gift Card Balance Best Buy Credit Card Affiliates Program Offer Sign-Up Rebates Warranties Service Plans PC Upgrades Repairs Replacement Parts Software End User License Agreement Car Home Entertainment Satellite Appliances Welcome . Please create an account or Sign in . Your Cart Contains 0 items Subtotal: $0.00 View Cart | Checkout Your Account Best Buy Credit Order Status Wish List Gift Cards Order Status Shipping Rates Returns Rebates Store Pickup Site Map Performance Plans Your California Privacy Rights Conditions of Use | Legal Policies | Privacy Policy Online prices and selection generally match our retail stores, but may vary. Prices and offers are subject to change. © 2003-2004 Best Buy. All rights reserved. For personal, noncommercial use only.

Gifts For Men

Birthday Gifts & Men's Gift Ideas - Boyfriend's Presents & Gift Ideas For Men & Birthday Gifts Below you will find a unique selection of Mens Gifts & Gift Ideas For Your Boyfriend, including a Mini Table Football Game and an Electric Shock Lighter. Looking for birthday gifts and men's gift ideas? Mini Table Football Score with this action-packed tabletop football game. Despite it's compact size, this great game still has all the fun and exciting features of the larger game that everyone loves. It has a goal counter each end, and three rods on each side. Price: £ 19.95 | More Info Casino Dice These are no ordinary dice as they been used in actual casino play in Las Vegas. Casinos retire dice after about eight hours, and you can be sure that these dice will have won and lost $ Millions, even before you take them out the packet. Price: £ 4.95 | More Info Electric Shock Lighter It may look like a stylishly designed lighter on the outside, but anyone attempting to use it gets a nasty but harmless electric shock. Perfect payback for anyone who is always borrowing your lighter but never gives it back. Price: £ 5.95 | More Info Heebeegeebee Head Massager Relax and massage away your troubles with this new battery powered head massager. Sure to relieve stress, get rid of tension and soothe you into a state of bliss- and there's no excuse- anybody can use it so grab your partner, friends or even kiddies and indulge! Price: £ 19.95 | More Info USB Swiss Army Knife - With 128MB Memory A swiss army knife with a detachable USB storage device, making it ideal for business men & women. Whether you want to store/move/transfer, digital photos, MP3s, work files etc...this has to be the most functional way to do it. It’s also made by Victorinox, so it’s the real deal, and It even has a built-in pen and LED pointer for presentations. Price: £ 69.95 | More Info Shocking Roulette Four players place their finger in one of the victim slots and then start the roulette lights running. It will select one of the players at random to receive a shock to the system, and is a test of nerve to see who is brave enough to keep their finger in the slot. When the beeping stops....the screaming starts! Price: £ 14.95 | More Info Radio Pen Never be without your favourite sounds with this cool & discreet Radio Pen. Scan to your favourite FM stations with a single touch, and listen to the quality crisp sound. The detachable ball point pen clips easily to your clothing for hands free listening. Price: £ 9.95 | More Info Fliklite Torches Machined out of solid aluminium, the Fliklite looks and feels like something out of NASA's R&D department. Its four LEDs burn brightly - for around 50 hours. The original aluminium model is waterproof to 30 metres, while the brand new LS3 is waterproof to an ear popping 100 Metres and is visible from 7 miles!! AL1 - Price: £ 29.95 | LS3 - Price: £ 64.95 | More Info Parking Keyring Timer This timer keyring, has a cool silver design, and will go off 5 minutes before your meter runs out, and again when your time hits zero. A great gadget for anyone with a car. Price: £ 4.95 | More Info USB Mobile Phone Charger There's nothing worse than arriving at the office, and finding your mobile phone in a state of exhaustion, and having to go the whole day in a state of communication meltdown. Now all this is the thing of the past with the aid of this USB phone charger, that refuels your phone from any computer. Price: £ 8.95 | More Info For a larger selection of Men's Gifts & Gift Ideas For his Birthday, just CLICK HERE Best Sellers Gifts Home | Men's Gifts | Wedding Gifts | Kids Gifts | Anniversary Gift Ideas | Birthday Presents | Women's Gifts | Husband's Gifts Gifts for Boyfriends | Corporate Gifts | Valentines Day Gift Ideas | Christmas Presents