Number System 4550 ÷ 25% of ? = 130 125 135 140 130 125 135 140 130 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 4550 ÷ ? x 25/100 = 130= 4550 ÷ ?/4 = 130= 4550 x 4/? = 130= ? x 130 = 4550 x 4= ? = 4550 x 4/130 = 140
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 {3√4913}² = ? 225 333 289 121 225 333 289 121 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? = (3√4913)² = (17)² = 289
Number System If (83)² is subtracted from the square of a number, the answer so obtained is 8487. What is the number ? 179 163 124 146 179 163 124 146 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x Therefore, x² - (83)² = 8487x² = 8487 + (83)²x² = 8487 + 6889x² = 15376Therefore, x² = 15376 x = 124
Number System Two numbers are in the ratio 3:5. If 9 be subtracted from each, they are in the ratio of 9:17. The first number is: 36 18 30 27 36 18 30 27 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (3x-9):(5x-9) = 9:17 x = 12 => 3x = 36
Number System 9 3/4 + 7 2/17 - 9 1/15 = ? 7 817/1020 7 719/1020 9 719/1020 9 817/1020 7 817/1020 7 719/1020 9 719/1020 9 817/1020 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Given sum = 9 + 3/4 + 7 + 2/17 - (9 + 1/15)= (9 + 7 - 9) + (3/4 + 2/17 - 1/15)= 7 + (765 + 120 - 68)/1020 = 7 817/1020