Number System In how many different ways can the letters of word "SENTENCE" be arranged ? 3260 2360 3360 6460 3260 2360 3360 6460 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Number of ways = 8!/3! 2! = 40320/12 = 3360
Number System If x + y = 61 and xy = 888, What is the value of x²+ y² ? 1955 1975 1965 1945 1955 1975 1965 1945 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 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 90/190 91/190 89/190 92/190 90/190 91/190 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
Number System Find the least number when successively divided by 2, 3 and 7 leaves remainders 1, 2 and 3 respectively? 67 65 61 75 67 65 61 75 ANSWER DOWNLOAD EXAMIANS APP
Number System The product of two consecutive odd numbers is 4623. What is the product of the next two consecutive odd numbers ? 8795 6782 5183 7745 8795 6782 5183 7745 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP √4623 = 6767 x 69 = 4623∴ Required product = 71 x 73 = 5183
Number System A bag contains four red, six black and seven green balls. Three balls are drawn randomly. What is the probability that the balls drawn contain exactly two red balls ? 51/340 45/340 58/340 39/340 51/340 45/340 58/340 39/340 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Total balls = 4 + 6 + 7 = 17∴ n(S) = 17C1 = 680Two red balls can be selected from four red balls in 4C2 = 6 ways.and the third ball can be selected from the remaining 13 balls in 13C1 = 13 ways.∴ P (E) = 13x6/680 = 39/340
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