Number System Which one of the following is the sum of the numbers 1, 3, 5, 7, 9…. up to nth number? N(N + 1)/2 N2 N(N + 1) N2 + 1 N(N + 1)/2 N2 N(N + 1) N2 + 1 ANSWER DOWNLOAD EXAMIANS APP
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 If the difference between a number and two-fifths of that number is 45 what is the number ? 77 78 75 76 77 78 75 76 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x ∴ x - 2x/5 = 45∴ x = 75
Number System Ratio between two numbers is 3: 4 and their sum is 420. Find the smaller number? 240 180 140 160 240 180 140 160 ANSWER DOWNLOAD EXAMIANS APP
Number System In a division sum, the remainder is 0. As student mistook the divisor by 12 instead of 21 and obtained 35 as quotient. What is the correct quotient? 12 13 20 0 12 13 20 0 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Number = (12 * 35) = 420Correct quotient = 420/21 = 20
Number System Find the least number with which 16200 should be multiplied, to make it a perfect cube. 48 45 360 36 48 45 360 36 ANSWER DOWNLOAD EXAMIANS APP
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