Number System If (17)3 is subtracted from the square of a number, the answer so obtained is 2143. What is the number ? 81 84 82 83 81 84 82 83 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x² - (17*17*17) = 2143or x² = 2143 + 4913 = 7056∴ x = 84
Number System If x + y = 61 and xy = 888, What is the value of x²+ y² ? 1945 1955 1975 1965 1945 1955 1975 1965 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 What is the sum of 1 + 2 + 3+ ... + 27 ? 378 396 382 343 378 396 382 343 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Sum = 27 x (27 + 1)/2= 27 x 28/2= 27 x 14= 378
Number System What is the difference between the local value of 7 and 5 in the number 2574? 413 403 570 430 413 403 570 430 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 500 – 70 = 430
Number System Two third of three- fifth of one fourth of a number is 24, what is 30% of that number? 42 90 72 69 42 90 72 69 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x * 2/3 * 3/5 * 1/4 = 24x = 240240 * 30/100 = 72
Number System In how many different ways can the letters of the word 'FRUGAL'be arranged ? 515 720 556 660 515 720 556 660 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In FRUGAL there ae six difference letters Therefore, 6 ! = 6 x 5 x 4 x 3 x 2 x 1 = 720
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