Number System When (21)² is subtracted from the square of a number the answer obtained is 1584. What is the number ? 35 55 65 45 35 55 65 45 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.According to the question,x² - (21)² = 1584= x² - 441 = 1584 = x² = 1584 + 441 = 2025∴ x = √2025 = 45
Number System If (35)² is added to the square of a number the answer so obtained is 1394. What is the number ? 15 11 13 17 15 11 13 17 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x Therefore, x² + (35)² = 1394Therefore, x² = 1394 - (35)² = 1394 - 1225 = 169Therefore, x = √169 = 13
Number System The difference between a positive proper fraction and its reciprocal is 9/20. The fraction is: 4/5 3/5 3/10 5/4 4/5 3/5 3/10 5/4 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 1/x - x = 9/20 20x2 + 9x - 20 = 0 20x2 + 25x - 16x - 20 = 0 5x(4x + 5) -4(4x + 5) = 0(4x + 5)(5x - 4) = 0x = 4/5
Number System A number consists of two digits. If the digits interchange places and the new number is added to the original number, then the resulting number will be divisible by: 9 3 5 11 9 3 5 11 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the ten's digit be x and unit's digit be y. Then, number 10x + y.Number obtained by interchanging the digits = 10y + x.(10x + y) + (10y + x) = 11(x + y)which is divisible by 11.
Number System A canteen requires 17 dozen of eggs per week. How many eggs will it require from January 1 to February 11 ? 1224 987 525 820 1224 987 525 820 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Number of days from Jan 1 to Feb 11th= 31 + 11 = 42 days = 6 weeks∴ Total eggs =17 x 12 x 6 = 1224
Number System The sum of three consecutive even numbers is 252. What is the sum of the smallest and the largest numbers? 170 171 169 168 170 171 169 168 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 168
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