Number System If (74)² is added to the square of a number the answer so obtained is 7780. What is the number ? 49 48 50 47 49 48 50 47 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.or, x² + (74)² = 7780or, x² = 7780 - 5476 = 2304∴ x = 48
Number System If the product of two successive positive integers is 4692, what is the smaller number ? 66 68 70 64 66 68 70 64 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ∵ 68 x 69 = 4692
Number System In how many different ways can be the letters of the word PENCIL be arranged among themselves ? 720 860 510 640 720 860 510 640 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 What should come in place of question mark (?) in the following number series ? 7, 176, 480, 1058, 2188, 4426, ? 8884 8881 8882 8888 8884 8881 8882 8888 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Series is (No. + 9²) x 2, (+8²) x 2, (+7²) x 2, (+6²) x 2.......
Number System The difference between a two-digit number and the number obtained by interchange the two digits of the number is 27. If the sum of the two digits of the number is 13, what is their product ? 40 37 38 39 40 37 38 39 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be 10x + y.∴ 10x + y - (10y + x) = 27or 9x - 9y = 27∴ x - y = 3 .......(I)x + y = 13 .......(II)From eqn (I) and (II)x = 8 and y = 5.So the number = 85Therefore, product = 8 x 5 = 40
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