Number System If the sum and difference of two numbers are 20 and 8 respectively, then the difference of their square is: 160 28 180 12 160 28 180 12 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 What should come in place of question mark (?) in the following number series ? 7, 176, 480, 1058, 2188, 4426, ? 8882 8884 8888 8881 8882 8884 8888 8881 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Series is (No. + 9²) x 2, (+8²) x 2, (+7²) x 2, (+6²) x 2.......
Number System When 732 is subtracted form the square of a number, the answer that is obtained is 5280. What is the number? 99 97 101 103 99 97 101 103 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x2 - 732 = 5280 x2 = 5280 + (70+3)2 = 5280 + 4900 + 420 + 9 = 10609= 10000 + 2(100)(3) + 32 = (100 + 3)2x = 100 + 3 = 103.
Number System In how many different ways can be the letters of the word PENCIL be arranged among themselves ? 640 720 510 860 640 720 510 860 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Total six letters are there and hence the number of arrangements = 6! = 6 x 5 x 4 x 3 x 2 x 1 = 720
Number System If the product of two successive positive integers is 4692, what is the smaller number ? 70 64 66 68 70 64 66 68 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ∵ 68 x 69 = 4692
Number System In how many different ways can the letters of word 'BIOLOGY' be arranged ? 2410 2678 2520 2367 2410 2678 2520 2367 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In BIOLOGY total 7 letters are there but O comes twice.∴ Number of arrangements = 7!/2! = 2520
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