Number System If one-seventh of a number is 55 then 40% of that number = ? 147 163 171 154 147 163 171 154 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the no. be x , Therefore, x/7 = 55Therefore, x = 55 x 7 = 385Therefore, 49% of 385 = 154
Number System What is the value of ? in the following equations ? 72/? = ?/50 100 60 40 80 100 60 40 80 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (?)² = 72 x 50= (6 x 6 x 2) x (5 x 5 x 2)= (6 x 5 x 2)² = (60)²∴ ? = 60
Number System Sum of the digits number is 8 and their product is 12. Find the difference between the digits? 4 6 2 None 4 6 2 None ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x + y = 8xy = 12(x – y)2 = (x + y)2 – 4xy (x – y)2 = 64 – 48 => (x – y) = 4
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 80/150 80/153 80/151 80/152 80/150 80/153 80/151 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 a number is subtracted from its square we get 272. Find the number? 24 22 14 17 24 22 14 17 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x2 – x = 272 => x =17
Number System 3√68921 = ? 51 31 21 41 51 31 21 41 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? = 3√68921= 3√41 x 41 x 41= 41
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