Number System In how many ways can 5 boys be chosen from 6 boys and 4 girls so as to include exactly one girl ? 60 54 58 56 60 54 58 56 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 4550 ÷ 25% of ? = 130 140 125 135 130 140 125 135 130 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 What is the greater of the two numbers whose product is 2560, given that the sum of the two numbers exceeds their difference by 64? 90 110 None of these 100 90 110 None of these 100 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the greater and the smaller number be g and s respectively.gs = 2560g + s exceeds g - s by 64 i.e., g + s - (g - s) = 64i.e., 2s = 64 => s = 32.g = 2560/s = 80.
Number System One half of a two digit number exceeds its one third by 6. What is the sum of the digits of the number? 5 7 3 9 5 7 3 9 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x/2 – x/3 = 6=> x =63 + 6 = 9
Number System Find the average of the following set of scores 450, 1050, 12, 390, 143, 286, 550, 999 490 485 495 480 490 485 495 480 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Required average score = (450 + 1050 + 12 + 390 + 143 + 286 + 550 + 999) / 8 = 3880 / 8 = 485
Number System A basket contains 5 blue, 4 green and 3 red ball. If three balls are picked at random, what is the probability that at least one is red ? 32/51 34/55 37/52 31/58 32/51 34/55 37/52 31/58 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Probability of having no red ball is9C3 / 12C3 = 21/55Probability of having at least one red ball is 1 - 21/55 = 34/55
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