Number System The difference between 8% of a number and 3% of the same number is 39. What is 2.8% of that number ? 25.84 27.84 24.84 21.84 25.84 27.84 24.84 21.84 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.∴ x(8 - 3)% = 39x = 3900/5 = 780∴ 2.8% of 780= 780 x 2.8/100 = 21.84
Number System Which number should replace question mark (?) in the following equation ? ?/342 = 38/? 118 112 116 114 118 112 116 114 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (?)² = 342 x 38Therefore, ? = √342 x 38 = √38 x 9 x 38 = 38 x 3 = 114
Number System In how many different ways can be the letters of the word PENCIL be arranged among themselves ? 510 860 720 640 510 860 720 640 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Total six letters are there and hence the number of arrangements = 6! = 6 x 5 x 4 x 3 x 2 x 1 = 720
Number System The sum of a number and its reciprocal is one-eighth of 34. What is the product of the number and its square root? None of these 27 32 8 None of these 27 32 8 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x. Then,x + 1/x = 34/8 8x2 - 34x + 8 = 0 4x2 - 17x + 4 = 0 (4x - 1)(x - 4) = 0 x = 4required number = 4 * √4 = 4 * 2 = 8.
Number System A box contains 5 red, 4 black and 4 blue balls. If 3 balls are drawn randomly from the box, what is the probability that there are exactly 2 blue balls in the three drawn balls ? 27/143 28/144 30/146 29/145 27/143 28/144 30/146 29/145 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Total balls = 5 + 4 + 4 = 13∴ n(S) = 13C3 = 2862 blue balls can be selected from 4 balls in 4C2 = 6 ways and the remaining one ball is to be selected from 9 balls in 9C1 = 9 ways ∴ n(E) = 6 x 9∴ P(E) = 6 x 9/286 = 27/143
Number System Of an amount, 20% of 25% of 30% is Rs 75. Then what is the original amount ? Rs. 2000 Rs. 5000 Rs. 3000 Rs. 4000 Rs. 2000 Rs. 5000 Rs. 3000 Rs. 4000 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the amount be x.∴ X x 20/100 x 25/100 x 30/100 = 75∴ X = 75 x 5 x 4 x 10/3 = 5000
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