2. One wheel of the cart is 3 times larger than the other. The big wheel has made over 1000 rotations on the path. How many rotations has the smaller wheel made?
3. A person answers questions with "yes" or "no". He has the right not to say truth only once. With how many questions you can guess what number he/she thinks of, if that number is from 1 to 4?
4. There are 8 coins. One of them is fake and it is lighter. There are pan scales. In how many weighings you can find fake coin?
5. There are two cans of water: large and small. The large can has 5 times more water than the small can. The small can has 8 oz less water than the large can. How much water is in each can?
6. The length of the room is 20 ft. The snail moves from one side of the room to another. During the day the snail moves 2 ft towards the end of the room, but during the night the snail moves back 1 ft. In how many days will the snail reach the end of the room?
7. What is the missing number? (587 + 213 + 111) x ? = 0
8. How many rooks can be arranged on a chessboard such that none of them threaten the other?
Examples of correct answers:
9. Two tourists were making sandwiches. Third tourist came, and the first two tourists gave him something to eat: the first gave him 3 sandwiches, and the second 2 sandwiches. The third tourist paid them $10. How do the first two tourists need to divide money among themselves?
10. Grandfather is 56 years old and his granddaughter is 14. In how many years grandfather's age will be twice as much as his granddaughter's?