Number System 4550 ÷ 25% of ? = 130 135 130 140 125 135 130 140 125 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 4550 ÷ ? x 25/100 = 130= 4550 ÷ ?/4 = 130= 4550 x 4/? = 130= ? x 130 = 4550 x 4= ? = 4550 x 4/130 = 140
Number System The sum of the digits of a two-digit number is 12, and the difference between the number and the number obtained by interchanging the two digits of the number is 18. Find the number. 75 12.5 50 25 75 12.5 50 25 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be 10x + y.∴ x + y = 12 ...........(i)10x + y - (10x + x) = 18or 10x + y - 10y - x = 18or 9x - 9y = 18∴ x - y = 2From (i) and (ii), x = 7, y = 5∴ Number = 75
Number System If x + y = 61 and xy = 888, What is the value of x²+ y² ? 1945 1955 1965 1975 1945 1955 1965 1975 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 difference between 71% of a number and 46% and of the same number is 212. What is 75% of that number 636 845 724 673 636 845 724 673 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.∴ 71% of x - 46% of x = 212∴ (71 - 46)% of x = 212∴ 25/100 x x = 212∴ x = 212 x 4 = 848∴ 75% of 848 = 848 x 75/100 = 636
Number System If (72)² is subtracted from the square of a number, the answer thus obtained is 4617. What is the number ? 95 99 103 92 95 99 103 92 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x² - (72)² = 467Therefore, x² = 4617 + 5184Therefore, x² = 9801 Therefore, x = 99
Number System How many figures are required for numbering the pages of a book containing 1000 pages? 3892 6489 2893 2883 3892 6489 2893 2883 ANSWER DOWNLOAD EXAMIANS APP