Number System If the sum and difference of two numbers are 20 and 8 respectively, then the difference of their square is: 160 180 28 12 160 180 28 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.
Number System Complete the series : 81, 69, 58, 48, 39 ........ 29 28 30 31 29 28 30 31 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 31
Number System How many numbers up to 300 and 700 are divisible by 2, 3 and 7 both together? 9 11 8 10 9 11 8 10 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (700 – 300)/42 = 9 22/42 => 9 Numbers
Number System A number is doubled and 9 is added. If the resultant is trebled, it becomes 75. What is that number? 6 8 None of these 3.5 6 8 None of these 3.5 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x. Then,3(2x + 9) = 752x = 16 => x = 8
Number System The average of five consecutive even numbers A, B, C, D and E is 42. What is the product of B and D ? 3289 4589 2476 1760 3289 4589 2476 1760 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP A + B + C + D + E/5 = 42∴ C = 42, ∴ B = 40, ∴ D = 44∴ B x D = 40 x 44 = 1760
Number System A basket contains eight white and ten black balls. Two draws of one ball each are made without replacement. What is the probability that one ball is white and the other ball is black ? 80/151 80/150 80/153 80/152 80/151 80/150 80/153 80/152 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Two balls can be drawn from 18 balls in 18C2 Ways, ie 153 ways. One white from 8 white balls can be drawn in 8C1 = 8 ways and one black ball from 10 black can be drawn in 10C1 = 10 ways.∴ n(S) = 153, n(E) = 8 x 10 = 80∴ P(E) = 80/153
EXAMIANS