Math Riddles Page 14 of 26
Math riddles, math questions and math problems, here are some hard math riddles and hard math problems.
131. What number comes next in the following sequence?
2, 6, 6, 12, 10, 18, 14, 24, ?
132. The impetuous young man was telling his fianc? what time he would be at her house so they could elope. He wanted to arrive at midnight, so he had done a few practice runs. If he drove 40 miles per hour, he'd be an hour early. If he drove at 30 miles per hour, he'd be on time, but at 20 miles per hour, he'd be two hours late. How far away was he?
133. Insert + or - between the numbers to make the equation work:
8 7 6 5 4 3 2 1 = 68
If you don't place a symbol between numbers, they merge to form a multi-digit number.
134. Five kids entered a contest to guess how many jelly beans were in a jar. Alice guessed 45, Betty guessed 39, Charlie guess 49, Don guessed 50 and Earl guessed 47. One of them was off by 6, one by 5, one by 2, and one by 4. One was right. How many marbles were in the jar?
135. What is the 4-digit number (no zeros) in which the first digit is one-eighth of the last digit, the second digit is the sum of the first and last digits and the third digit is twice the first? This is too easy, try to do it in your head!
136. In a duty free store, Jack bought a suit for $200. This included a 10% tax for stain protection, and a 10% tax for service charge to exchange his dollars into pesos and a 5% tip for the salesman. ( the extra charges were based on the original price. ) How much would the suit have cost without all the extras.
137. Mary is a champion weightlifter. If she weighs 120 pounds plus a third of her own weight, how much does she weigh?
138. Write the number 76 using three consecutive numbers between 1 and 9 inclusive, using each number once only. You may use any of the mathematical operational signs: +, -, x and ?
139. There are 3 cups and 10 coins on the table. You are asked to distribute the coins in the 3 cups according to the following 2 conditions: a: there must be no empty cups; b: there must be 7 coins in one cup and 3 in another.
140. What is the lowest common denominator of:
1/10, 1/9, 1/8, 1/7, 1/6, 1/5, 1/4, 1/3, 1/2
