Number System What should come in the place of ' ? ' in the following number series ? 2, 5, 9, 19, 37, ? 78 75 77 76 78 75 77 76 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 2 x 2 + 1 = 5;5 x 2 - 1 = 99 x 2 + 1 = 19: 19 x 2 - 1 = 3737 x 2 + 1 = 75
Number System The difference between a two-digit number and the number obtained after interchanging its two digits is 36. The sum of the two digits of the number is 12. Find the lowest such possible number. 48 47 50 49 48 47 50 49 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the digits be x and yTherefore, x + y = 12 .............(1)(10y + x) - (10x + y) Therefore, y - x = 4............. (2)Solving (1) and (2), y = 8 Therefore, x = 4There are two possible numbers 48 and 84. So the lowest no. is 48.
Number System If the numerator of a fraction is decreased by 12.5% and the denominator is increased by 180% the resultant fraction is 1/2. What is the original fraction ? 7/5 1/5 3/5 8/5 7/5 1/5 3/5 8/5 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the original fraction be x/y.∴ x x 87.5/100/y x 280/100 = 1/2or 87.5x/280y = 1/2∴ 175x = 280y∴ x/y = 280/175 = 8/5
Number System The sum of the two numbers is 12 and their product is 35. What is the sum of the reciprocals of these numbers? 35/8 7/32 12/35 1/35 35/8 7/32 12/35 1/35 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the numbers be a and b. Then,a + b = 12 and ab = 35.(a + b)/ab = 12/35= (1/b + 1/a) = 12/35Sum of reciprocals of given numbers = 12/35.
Number System The sum of a number and its reciprocal is one-eighth of 34. What is the product of the number and its square root? None of these 8 27 32 None of these 8 27 32 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x. Then,x + 1/x = 34/8 8x2 - 34x + 8 = 0 4x2 - 17x + 4 = 0 (4x - 1)(x - 4) = 0 x = 4required number = 4 * √4 = 4 * 2 = 8.
Number System If the sum and difference of two numbers are 20 and 8 respectively, then the difference of their square is: 28 160 180 12 28 160 180 12 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the numbers be x and y. Then, x + y = 20 and x - y = 8x2 - y2 = (x + y)(x - y) = 20 * 8 = 160.
EXAMIANS