Number System If x + y = 61 and xy = 888, What is the value of x²+ y² ? 1945 1965 1975 1955 1945 1965 1975 1955 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 7589 - ? = 3434 4155 1123 11023 4242 4155 1123 11023 4242 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let 7589 - x = 3434Then x = 7589 - 3434 = 4155
Number System If (35)² is added to the square of a number the answer so obtained is 1394. What is the number ? 11 13 17 15 11 13 17 15 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 Twenty-First Century will start on January 1 in the year 2000 2101 2100 2001 2000 2101 2100 2001 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 2001
Number System The difference between the two digit number and the number obtained by interchanging its digits is 54. The difference between the digits is? Nothing can be said. 4 1 6 Nothing can be said. 4 1 6 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (10x + y) – (10y + x) = 54x – y = 6
Number System The sum of a number and its reciprocal is one-eighth of 34. What is the product of the number and its square root? None of these 27 32 8 None of these 27 32 8 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x. Then,x + 1/x = 34/8 8x2 - 34x + 8 = 0 4x2 - 17x + 4 = 0 (4x - 1)(x - 4) = 0 x = 4required number = 4 * √4 = 4 * 2 = 8.
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