Number System What value should come in place of ? in the given number series ? 15, 51, 162, 498, 1509, ? 5656 7878 3434 4545 5656 7878 3434 4545 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 15, (15 + 2) x 3 = 51,(51 + 3) x 3 = 162, (162 + 4) x 3 = 498, (498 + 5) x 3 = 1509(1509 + 6) x 3 = 4545
Number System When (21)² is subtracted from the square of a number the answer obtained is 1584. What is the number ? 55 65 35 45 55 65 35 45 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.According to the question,x² - (21)² = 1584= x² - 441 = 1584 = x² = 1584 + 441 = 2025∴ x = √2025 = 45
Number System When 102 is reduced from a number, the number gets reduced by 88%. What is that number ? 550 850 750 650 550 850 750 650 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 850
Number System Of the three numbers, second is twice the first and is also thrice the third. If the average of the three numbers is 44, the largest number is 44 56 72 38 44 56 72 38 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 72
Number System If A + B = 30 and AB = 94, What is the value of A² + B² ? 625 920 712 824 625 920 712 824 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (A + B)² = (30)² = 900A² + B² + 2AB = 900Therefore, A² + B² = 900 - 2 x 94 = 900 - 188 = 712
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 90/190 91/190 89/190 92/190 90/190 91/190 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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