Number System If the numerator of a fraction is decreased by 12.5% and the denominator is increased by 180% the resultant fraction is 1/2. What is the original fraction ? 7/5 1/5 3/5 8/5 7/5 1/5 3/5 8/5 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the original fraction be x/y.∴ x x 87.5/100/y x 280/100 = 1/2or 87.5x/280y = 1/2∴ 175x = 280y∴ x/y = 280/175 = 8/5
Number System The average of 7 numbers is 15, that of the first three is 6 and that of the last three is 23. What is the fourth number? 7 13 18 15 7 13 18 15 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 4th No. = (Total of 7 Nos) - (Total of first three + total of last 3) = (15 x 7) - (6 x 3 + 23 x 3) = 105 - (18 + 69) =105 - 87 = 18
Number System A number when multiplied by five times of itself give the value equal to 1445. What is the number ? 16 17 15 18 16 17 15 18 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x x 5x = 1445= 5x² = 1445= x² = 289∴ x = 17
Number System The product of two consecutive position odd numbers is 6723. What is the smaller number? 79 71 74 83 79 71 74 83 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP n x (n + 2) = 6723= n² + 2n - 6723 = 0= n² + 83n - 81n - 6723 = 0= n(n + 83) - 81 (n + 83) = 0Therefore, (n - 81) (n + 83) = 0Therefore, n = 81, n + 2 = 83
Number System If (72)² is subtracted from the square of a number, the answer thus obtained is 4617. What is the number ? 103 99 95 92 103 99 95 92 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x² - (72)² = 467Therefore, x² = 4617 + 5184Therefore, x² = 9801 Therefore, x = 99
Number System What should come in place of question mark (?) in the following number series ? 7, 176, 480, 1058, 2188, 4426, ? 8884 8881 8888 8882 8884 8881 8888 8882 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Series is (No. + 9²) x 2, (+8²) x 2, (+7²) x 2, (+6²) x 2.......
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