Number System If the fractions8/5,7/2,9/5,5/4,4/5 are arranged in descending order of their values, which one will be fourth? 1/3 11/13 5/4 7/9 1/3 11/13 5/4 7/9 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 5/4
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 ? 89/190 92/190 91/190 90/190 89/190 92/190 91/190 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 Find the number, when 15 is subtracted from 7 times the number, the result is 10 more than twice of the number 7.5 5 4 15 7.5 5 4 15 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.7x -15 = 2x + 10 => 5x = 25 => x = 5
Number System What is the sum of 1 + 2 + 3+ ... + 27 ? 396 378 343 382 396 378 343 382 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Sum = 27 x (27 + 1)/2= 27 x 28/2= 27 x 14= 378
Number System In how many ways can 5 boys be chosen from 6 boys and 4 girls so as to include exactly one girl ? 56 58 60 54 56 58 60 54 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP One girl can be chosen in 4C1 = 4 ways and 4 boys can be chosen in 6C4 = 15 ways ∴ Total number of ways = 4 x 15 = 60 ways.
Number System 106 * 106 - 94 * 94 = ? 2000 1906 2400 1904 2000 1906 2400 1904 ANSWER DOWNLOAD EXAMIANS APP
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