Grab Your Pen and Paper to Solve These Brain Teasers
If you try to work through the answers to these brain teasers in your head, you may find they’re pretty tricky. Once you grab your trusty pen and a sheet of paper, though, you’ll see that writing them down can make all the difference.
1 of 5
A boy had some baseball cards that he wants to trade with his friends. He gave half of his cards to one boy, who gave him eight cards in return. He gave half of his cards to another friend, who gave him four in return. He then gave three quarters of his cards to a third friend, who gave him four in return. At the end of these swaps, he had eight cards. How many did he start with?
20 cards
32 cards
48 cards
64 cards
2 of 5
A farmer needs to cross a river with a fox, a chicken, and a bag of corn. His boat is small, so he can only carry across one at a time. He can never leave the fox alone with the chicken or the chicken alone with the bag of corn. Which one must he take on his first trip across the river?
Fox
Chicken
Bag of corn
ANSWER: The farmer takes over the chicken first, then the fox. He then brings the chicken back to the original shore and takes the bag of corn over to the fox. He then returns for the chicken.
3 of 5
Two girls have some marbles. Girl 1 says to her friend, “If you give me one of your marbles, then I will have as many as you.” Girl 2 replied, “No, but if you give me one of your marbles, then I will have twice as many as you.” How many marbles did each of them have?
Girl 1 has 2, Girl 2 has 4
Girl 1 has 3, Girl 2 has 5
Girl 1 has 4, Girl 2 has 6
Girl 1 has 5, Girl 2 has 7
4 of 5
Fred and Bill’s combined ages are 44 years. Fred is twice as old as Bill was when Fred was half as old as Bill will be when Bill is three times as old as Fred was when Fred was three times as old as Bill. How old is Fred?
25 years
27.5 years
30 years
32.5 years
5 of 5
A frog is stuck in the bottom of a well that is 45 feet deep. He begins hopping up the sides to get out. Each day, he jumps up three feet into the well. However, he slips back down two feet every night. How many days does it take him to get out of the well?
42 days
43 days
44 days
45 days
ANSWER: At the end of the 42nd day, the frog is 42 feet from the bottom of the well. On the 43rd day, he reaches the top and never has a chance to slip back down.
