GSE Algebra I GSE Geometry GSE Algebra II GSE PreCalc Other Courses Calculus I Adv. Mathematical Decision Making Analytical Geometry ```CP-Statistics ``` `All Units` Coordinate Algebra Integrated Algebra I Integrated Geometry GPS Middle School Math GIVE BACK TO MATT Home >Brain Teasers > Classics Page 1

Review

Search Site:

 Page 1 Page 2 Page 3 Page 4 Page 5 Page 6

Classic Brain Teasers and Riddles

(Click on the question to see the answer.)

 1 If Jennifer has two U.S. coins that total 55 cents. One is not a nickel. What are the two coins?
 ANSWER One is a half dollar and the other coin is a nickel. It just said that one of the coins is not a nickel not both.

 2 If you start out with one marble in a jar and double the amount of marbles in the jar every minute and the jar is full in 60 minutes then how many minutes does it take to fill the jar half way?
 ANSWER At 59 minutes the jar would be half full because in the next minute it will double which would completely fill the jar.

 3 Why did the museum fire an archaeologist after the archaeologist tried to prove to the museum that he found a coin with the date 300 B.C. on it?
 ANSWER A coin in 300 B.C. would use a different dating system. Our current dating system that uses B.C. translates to "Before Christ". This dating system wasn't used until much later (well after 300 B.C.) and the system counts backwards (e.g. 300 B.C. would represent 300 years before 0 A.D.). If a coin were truly stamped 300 B.C. in the year we now consider 300 B.C. it would be predicting correctly that Christ would be born 300 years after the coin was stamped.

 4 A small grill can grill two hamburgers at a time. In order to cook the meat you must allow each side of a hamburger to grill for one minute. What is the minimum time that you can cook 3 hamburgers in?

 5 A father (200 lbs.) and two daughters (100 lbs. each) need to cross a river with piranha. They have one boat. The boat only carries up to 200lbs. How can you get the family safely across the river? How many trips in the boat are necessary?

 6. Take six letters out of the set of letters to make sense out of it: B S A I N X L E A T N T E A R S

 7 A businessman had to leave for a business trip and had to pack a pair of socks for a one day trip. He didn’t want to wake his wife so he packed in the dark and couldn’t see. He had 8 brown socks and 10 black socks in his dresser. If he wants to ensure that he has at least one pair of socks, how many socks must he take with him?
 ANSWER Selecting 3 socks would ensure at least one pair of the same color. At worst, after the first two selections he would have one brown and one black sock. Then, on the third selection he would either get a brown or black either of which would create a pair of the same color.

 8 A camper was making a stew that required exactly 1 gallon of water. The only problem was that the camper only had a 5 gallon and 7 Gallon bucket. How can the camper use the two containers to measure exactly 1 gallon of water?
 ANSWER Fill the 5 gallon bucket and pour it in to the 7 gallon bucket. Fill the 5 gallon bucket and pour what you can (should be 2 gallons) in to the 7 gallon bucket. This will leave 3 gallons in the 5 gallon bucket. Empty the 7 Gallon bucket and pour the 3 gallons from the 5 gallon bucket in to the 7 gallon bucket. This should leave you with 4 gallons of space left in the 7 gallon bucket. Fill the 5 gallon bucket and pour what you can (should be 4 gallons) in to the 7 gallon bucket. This will leave you with exactly 1 gallon in the 5 gallon bucket.

 9 How can you add 2 coins to the arrangement shown on the right to make 10 rows of 3 pennies? (There are at least 2 different solutions.)

 10 With out picking up your pencil and only drawing four straight lines connect all of the dots.

 11 What comes next in the following sequence? O, T, T, F, F, S, S, _____ , _____, _____,.........
 ANSWER O, T, T, F, F, S, S, E ,N, T,......... (O)ne (T)wo (T)hree (F)our (F)ive (S)ix (S)even (E)ignt (N)ine (T)en ....

 12 What occurs once in a minute, twice in a moment, but not once in a split second?
 ANSWER The letter "M" occurs once in Minute, twice in a MoMent, but not once in a split second.

 13 Farmer Joe Bob Brown wishes to plant 10 apple trees in such a way that he creates 5 rows of 4 trees (rows do not have to be parallel and each cannot be collinear with any other row). How should he plant the trees?

 14 What comes next in the following sequence? JA, FE, MA, AP, _____ , _____, _____,.........
 ANSWER JA, FE, MA, AP, MA, JU, JU, AU, .... (JA)nuary (FE)bruary (MA)rch (AP)ril (MA)y (JU)ne (JU)ly (AU)gust (SE)ptember (OC)tober ....

 15 What mathematical operator or symbol can you place between 2 and 3 to get a number that is greater than 2 and less than 3?
 ANSWER If you put a decimal point between 2 and 3, we would have 2.3 which is greater than 2 but less than 3.

GO TO CLASSIC BRAIN TEASERS PAGE 2

 Contact Information: Matt Winking