Problems on Numbers for Exam

Q71. Thrice the square of a natural number decreased by 4 times the number is equal to 50 more than the number. The number is
(a) 5
(b) 7
(c) 11
(d) 12

Q72. Two fifth of two - seventh of one - third of a number is 12. What is the number ?
(a) 150
(b) 275
(c) 280
(d) 315

Q73. The difference between two positive numbers is 5. If the sum of the squares of these numbers is 325, then the sum of the numbers is
(a) 20
(b) 25
(c) 30
(d) 35

Q74. The number that should be added to both the numerator and denominator of 4²/9² so that the fraction becomes 4/9 is
(a) 28
(b) 36
(c) 42
(d) 56

Q75. A two digit number is such that the product of its digits is 3. When 18 is added to the number the digits are reversed. The number is
(a) 9
(b) 12
(c) 13
(d) 15

Q76. Three numbers are in the ratio 3 : 4 : 6 and their product is 1944. The smallest of these number is
(a) 5
(b) 7
(c) 8
(d) 9

Q77. Which of the following numbers is not a square of any natural number ?
(a) 34602
(b) 4096
(c) 15309
(d) 10000

Q78. The ratio of two numbers is 5 : 6. If sum of the numbers be 121, then the biggest number is
(a) 52
(b) 55
(c) 66
(d) 71

Q79. The ratio of two numbers is 9 : 10. If the difference between them is 5 then the smallest number is
(a) 45
(b) 47
(c) 51
(d) 55

Q80. If 3 is added to the denominator of a fraction it becomes 1/3 and if 4 is added to its numerator, it becomes 3/4. The fraction is
(a) 5/17
(b) 3/11
(c) 5/12
(d) 3/17

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