Number System If the sum of the two numbers is 22 and the sum of their squares is 404, then the product of the numbers is: 44 88 40 80 44 88 40 80 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the numbers be x and y. Then, (x + y) = 22 and x2 + y2 = 404 Now, 2xy = (x + y)2 - (x2 + y2) 2xy= 222 - 404 = 484 - 404 = 80xy = 40
Number System If x + y = 61 and xy = 888, What is the value of x²+ y² ? 1965 1945 1955 1975 1965 1945 1955 1975 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Because (x + y)² = x² + y² + 2xy∴ x² + y² = (x + y)² - 2xy∴ x² + y² = (61)² - 2 x 888= 3721 - 1776 = 1945
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 ? 80/151 80/152 80/153 80/150 80/151 80/152 80/153 80/150 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 (74)² is added to the square of a number the answer so obtained is 7780. What is the number ? 50 48 47 49 50 48 47 49 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.or, x² + (74)² = 7780or, x² = 7780 - 5476 = 2304∴ x = 48
Number System The difference between 8% of a number and 3% of the same number is 39. What is 2.8% of that number ? 24.84 27.84 25.84 21.84 24.84 27.84 25.84 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 What is 432 times 119 ? 51408 50408 53408 52408 51408 50408 53408 52408 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP No. 432 x 119 = 51408
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