Number System 432+2170+35=? 729 678 523 494 729 678 523 494 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 494
Number System If the sum of five consecutive even numbers A, B, C, D and E is 130, what is the product of A and E ? 780 720 660 840 780 720 660 840 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the consecutive even numbers be A = 2x, B = 2x + 2, C = 2x + 4, D = 2x + 6 and E = 2x + 8= A + B + C + D + E = 130= 10x + 20 = 130∴ x = 130 - 20/10 = 11Therefore, product of A and E= 22 x 30 = 660
Number System What is the sum of all the prime numbers from 20 to 40? 119 120 117 118 119 120 117 118 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 23 + 29 + 31 + 37 = 120
Number System What is the least number that should be added to 5200 to make it a perfect square ? 129 288 225 275 129 288 225 275 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 The product of two consecutive odd numbers is 6723. Find is the greater number. 80 83 77 85 80 83 77 85 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the first odd number be x.Then, the other odd number would be x + 2.∴ x(x+2) = 6723= x2 + 2x = 6723= x2 + 2x = 6723= x2 + 2x - 6723 = 0= x2 + 83 - 81 x - 6723 = 0= x(x+83) - 81 (x + 83) = 0= (x + 83) (x - 81) = 0= (x + 83) (x - 81) = 0= x - 81 = 0∴ x = 81Hence, greater number = x + 2 = 81 + 2 = 83
Number System If (17)3 is subtracted from the square of a number, the answer so obtained is 2143. What is the number ? 82 84 83 81 82 84 83 81 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x² - (17*17*17) = 2143or x² = 2143 + 4913 = 7056∴ x = 84
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