Number System The product of two consecutive position odd numbers is 6723. What is the smaller number? 71 74 79 83 71 74 79 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 What should come in the place of ' ? ' in the following number series ? 2, 5, 9, 19, 37, ? 76 78 75 77 76 78 75 77 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 2 x 2 + 1 = 5;5 x 2 - 1 = 99 x 2 + 1 = 19: 19 x 2 - 1 = 3737 x 2 + 1 = 75
Number System In how many different ways can the letters of word 'BIOLOGY' be arranged ? 2678 2367 2520 2410 2678 2367 2520 2410 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In BIOLOGY total 7 letters are there but O comes twice.∴ Number of arrangements = 7!/2! = 2520
Number System If the of a two-digit number are interchanged, the number so obtained is greater than the original number by 18. If the sum of the two digits of the number is 14. What is the original number ? 62 64 66 68 62 64 66 68 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the no. be 10x + y.No. formed by the interchange of digits = 10y + xWe have y - x = 2 .........(i)y + x = 14 .........(ii)Solving (i) and (ii), we get x = 6, and y = 8∴ the no. is 68.
Number System What is the least number that should be added to 5200 to make it a perfect square ? 288 225 275 129 288 225 275 129 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP We sec (73)² = 5329 and (72)² = 5184ie 5329 > 5200 > 5184So 129 should be added to make is perfect square.
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 ? 1/5 7/5 3/5 8/5 1/5 7/5 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
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