Number System If x + y = 61 and xy = 888, What is the value of x²+ y² ? 1955 1965 1945 1975 1955 1965 1945 1975 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Because (x + y)² = x² + y² + 2xy∴ x² + y² = (x + y)² - 2xy∴ x² + y² = (61)² - 2 x 888= 3721 - 1776 = 1945
Number System When 732 is subtracted form the square of a number, the answer that is obtained is 5280. What is the number? 103 97 99 101 103 97 99 101 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x2 - 732 = 5280 x2 = 5280 + (70+3)2 = 5280 + 4900 + 420 + 9 = 10609= 10000 + 2(100)(3) + 32 = (100 + 3)2x = 100 + 3 = 103.
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. 49 50 47 48 49 50 47 48 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 On dividing number by 5, we get 3 as remainder. What will be the remainder when the square of this number is divided by 5? 2 4 0 1 2 4 0 1 ANSWER DOWNLOAD EXAMIANS APP
Number System 148 x 3.75 x 4 = 111 x ? 17 19 24 20 17 19 24 20 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? = 148 x 3.75 x 4/111 = 20
Number System An urn contains 9 blue, 7 white and 4 black balls. If 2 balls are drawn at random, then what is the probability that only one ball is white ? 92/190 91/190 90/190 89/190 92/190 91/190 90/190 89/190 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Total possible outcomes = 20C2 = 20 x 19/1 x 2 = 190Total favourable outcomes = 7C1 x 13C1 = 7 x 13 = 91∴ Required probability = 91/190
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