Number System The difference between 8% of a number and 3% of the same number is 39. What is 2.8% of that number ? 27.84 24.84 21.84 25.84 27.84 24.84 21.84 25.84 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.∴ x(8 - 3)% = 39x = 3900/5 = 780∴ 2.8% of 780= 780 x 2.8/100 = 21.84
Number System The sum and the product of two numbers are 25 and 144 respectively, the difference of the number is? 5 11 3 7 5 11 3 7 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x + y = 25xy = 144(x- y)2 = (x + y)2 – 4xy(x- y)2 = 625 – 576 => (x – y) = 7
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 ? 91/190 89/190 92/190 90/190 91/190 89/190 92/190 90/190 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
Number System What is the average of the following set of numbers ? 173, 192, 198, 204, 211, 223, 227 210 234 204 222 210 234 204 222 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Avg = 173 + 192 + 198 + 204 + 211 + 223 + 227/7 = 1428/7 = 204
Number System In how many different ways can the letters of the word ANATOMY be arranged ? 2508 2510 2520 2504 2508 2510 2520 2504 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Here total letters are 7 but A comes twice.Therefore, Numbers of arrangements = 7!/2! = 2520
Number System Two numbers have a H.C.F of 16 and a product of two numbers is 2560. Find the L.C.M of the two numbers? 170 150 140 160 170 150 140 160 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP L.C.M of two numbers is given by(Product of the two numbers) / (H.C.F of the two numbers) = 2560/16 = 160.
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