Math Riddles Page 5 of 26
Math riddles and problems, there are all types of math riddles and difficulty levels, see how many you can solve.
41. What is the 4-digit number (no zeros) in which the first digit is the cube of two, the second and third digits are the first number doubled, and the fourth digit is the sum of the second and third?
42. A increased by 20% = B
B decreased by 50% = C
C increased by 25% = D
D decreased by 20% = E
What percent of A is E?
43. A two-digit number, read from left to right, is 4.5 times as large as the same number read from right to left. What is the number?
44. If 6 puzzle solvers can solve 12 puzzles in 12 minutes, how long should it take a single puzzle solver to solve 60 puzzles?
45. What is the missing number in the sequence below?
17 24 1 9 23 8 __? 13 27 35 12 19
46. The combined ages of Sharon and Doug total 16. In six years, Doug will be three-fourths of Sharon's age. In 10 years, he will be four-fifths of Sharon's age. How old are they now?
47. What is the next number in the following sequence?
2 6 12 48 96 480 960 5,760 11,520
_______?
48. Ann is now exactly two-fifths of her older sister's age, and two years from now she will be one-half of her older sister's age. Conversely, two years ago, Ann was only one-fourth the age of her older sister's age at that time. How old is Ann now? (She's a fairly young child, by the way.)
49. What number is 10 more than one-fourth of one-tenth of one-fifth of 800?
50. A bolt of cloth is colored as follows: one-third and one-quarter of it are black, the other 8 yards are gray. How long is the bolt?
