Number System How many figures are required to number the pages the pages of a book containing 365 pages? 897 977 967 987 897 977 967 987 ANSWER DOWNLOAD EXAMIANS APP
Number System A basket contains eight white and ten black balls. Two draws of one ball each are made without replacement. What is the probability that one ball is white and the other ball is black ? 80/152 80/151 80/150 80/153 80/152 80/151 80/150 80/153 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Two balls can be drawn from 18 balls in 18C2 Ways, ie 153 ways. One white from 8 white balls can be drawn in 8C1 = 8 ways and one black ball from 10 black can be drawn in 10C1 = 10 ways.∴ n(S) = 153, n(E) = 8 x 10 = 80∴ P(E) = 80/153
Number System If the sum and difference of two numbers are 20 and 8 respectively, then the difference of their square is: 160 180 12 28 160 180 12 28 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the numbers be x and y. Then, x + y = 20 and x - y = 8x2 - y2 = (x + y)(x - y) = 20 * 8 = 160.
Number System If the sum of four consecutive numbers is 370, which the following is the third lowest number among them 89 90 91 92 89 90 91 92 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the four consecutive numbers be x, (x + 1), (x + 2), (x + 3) thenx + (x + 1) + (x + 2) + (x + 3) = 370= 4x + 6 = 370∴ x = 364/4 = 91∴ third lowest number among them = x + 1= 91 + 1 = 92
Number System How many numbers between 300 and 800 can be by using digits 2, 4, 5, 6 and 0 ? 52 48 56 36 52 48 56 36 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ∴ Reqd . numbers = 3 x 4P2 = 3 x 12 = 36
Number System If the following fractions 7/6, 6/7, 5/3, 8/13 and 6/5 are arranged in descending order, which will be the last in the series? 8/13 6/13 7/13 9/13 8/13 6/13 7/13 9/13 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 7/6 = 1.166, 6/7 = 0.857,5/3 = 1.66,8/13 = 0.615,6/5 = 1.2Therefore, 5/3 > 6/5 > 7/6 > 6/7 > 8/13
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