Number System If the difference between a number and its three-fourth is 18, find the number. 72 61 57 68 72 61 57 68 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.According to the question,x - 3x/4 = 18= x/4 = 18= x = 4 x 18 = 72
Number System In a two-digit number, if it is known that its unit's digit exceeds its ten's digit by 2 and that the product of the given number and the sum of its digits is equal to 144, then the number is: 42 26 46 24 42 26 46 24 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the ten's digit be x. Then, unit's digit = x + 2. Number = 10x + (x + 2) = 11x + 2 Sum of digits = x + (x + 2) = 2x + 2 (11x + 2)(2x + 2) = 144 2x2 + 26x - 140 = 0 (x - 2)(11x + 35) = 0 x = 2Hence, required number = 11x + 2 = 24.
Number System (3² x 4² x 5) ÷ 36 = (?)² - 80 10 14 12 16 10 14 12 16 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (?)² = 3² x 4² x 5/36 + 80= 20 + 80 = 100∴ ? = √100 = 10
Number System Which one of the following numbers is exactly divisible by 11? 315624 245642 235641 415624 315624 245642 235641 415624 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (4 + 5 + 2) - (1 + 6 + 3) = 1, not divisible by 11.(2 + 6 + 4) - (4 + 5 + 2) = 1, not divisible by 11.(4 + 6 + 1) - (2 + 5 + 3) = 1, not divisible by 11.(4 + 6 + 1) - (2 + 5 + 4) = 0. So, 415624 is divisible by 11.
Number System The sum of the ages of a son and father is 65 years. After 5 years the age of father will be double of the age of son. What is the age of son ? 20 years 17 years 19 years 18 years 20 years 17 years 19 years 18 years ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the age of the son be x and the age of the father be y.Therefore, x + y = 65 ..........(i)or, 2 x (x + 5) = (y + 5)or, 2x + 10 = y + 5or, 2x - y = 5 ...................(ii)From equations (i) and (ii), x = 20, y = 45
Number System The difference between 45% of a number and 18% of the same number is 145.8. What is 30% of that number ? 162 245 141 188 162 245 141 188 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.45% of x - 18% of x = 145.8∴ x/100 (45 - 18) = 145.8∴ x = 145.8 x 100/27 = 540∴ 30% of 540 = 540 x 30/100 = 162
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