Number System If x + y = 61 and xy = 888, What is the value of x²+ y² ? 1955 1975 1965 1945 1955 1975 1965 1945 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 106 * 106 - 94 * 94 = ? 1906 1904 2400 2000 1906 1904 2400 2000 ANSWER DOWNLOAD EXAMIANS APP
Number System Three numbers are in ratio of 3: 4 :5. If the sum of first & third numbers is more than second number by 52, which will be largest number? 65 23 78 34 65 23 78 34 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 65
Number System The difference between a positive proper fraction and its reciprocal is 9/20. The fraction is: 3/5 5/4 4/5 3/10 3/5 5/4 4/5 3/10 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 How many numbers up to 100 and 300 are divisible by 11? 22 18 21 20 22 18 21 20 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (300 – 100)/11 = 200/11 = 18 2/1118 Numbers
Number System The difference between a two-digit number and the number obtained by interchanging its two digits is 45. The sum of the digit of the number is 9. What is the product of the two digits of the number? 13 15 12 14 13 15 12 14 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be 10x + y.Therefore, x + y = 9 ..................(i)10x + y - (10y + x) = 4510x + y - 10y - x = 45Therefore, x - y = 5 ..................(ii)From (i) and (ii), x = 7, y = 2Number = 72Therefore, = x x y = 7 x 2 = 14
EXAMIANS