Number System The sum of the squares of three numbers is 138, while the sum of their products taken two at a time is 131. Their sum is: 20 None of these 40 30 20 None of these 40 30 ANSWER DOWNLOAD EXAMIANS APP
Number System If x + y = 61 and xy = 888, What is the value of x²+ y² ? 1955 1975 1945 1965 1955 1975 1945 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 The peresent age of the father and the son are in the ratio of 8:3. After 12 years the ratio of their ages will be 2:1. What is the sum of the present age of the father and the son ? 67 years 69 years 66 years 68 years 67 years 69 years 66 years 68 years ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the present age of the father be 'x' and that of the son be 'y'. Then x/y = 8/3∴ 3x = 8y Further, x + 12/y + 12 = 2/1 ∴ x + 12 = 2y + 24 ∴ x - 2y = 12 ......(ii)From eqn (i) and (ii), x = 48, y = 18 ∴ sum = 66 yrs.
Number System 1827÷ 36 x ?=162.4 3.2 2.6 4.3 1.9 3.2 2.6 4.3 1.9 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 3.2
Number System If the sum of one-half of a number exceeds one-third of that number by 7 1/3, the number is: 20 15 30 18 20 15 30 18 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x. Then,(1/2 x + 1/5 x) - 1/3 x = 22/311/30 x = 22/3x = 20
Number System If the difference between the squares of two consecutive numbers is 47, what is the smaller number ? 23 26 24 25 23 26 24 25 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the numbers be (x + 1) and x.Therefore, (x + 1)² - x² = 47x² + 2x + 1 - x² = 472x + 1 = 47Therefore, x = 46/2 = 23
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