Number System If a + b = 16 and ab = 68, what is the value of a² + b² ? 124 120 112 116 124 120 112 116 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP a + b = 16 Therefore, (a+b)² = (16)² = 256 a² + b² + 2ab = 256Therefore, a² + b² = 256 - 2 x 68Therefore, a² + b² = 256 - 136 = 120
Number System If the fractions8/5,7/2,9/5,5/4,4/5 are arranged in descending order of their values, which one will be fourth? 11/13 1/3 5/4 7/9 11/13 1/3 5/4 7/9 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 5/4
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 The square root of 0.0081 is: 0.009 0.09 0.91 0.9 0.009 0.09 0.91 0.9 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 0.09
Number System Sum of the digits number is 8 and their product is 12. Find the difference between the digits? 2 None 4 6 2 None 4 6 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 (164 x 175) x ? = 258300 5 2 9 11 5 2 9 11 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? = 258300 / 164 x 175 = 9
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