Number System If the sum and difference of two numbers are 20 and 8 respectively, then the difference of their square is: 12 160 28 180 12 160 28 180 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the numbers be x and y. Then, x + y = 20 and x - y = 8x2 - y2 = (x + y)(x - y) = 20 * 8 = 160.
Number System In a 150-litre mixture of milk and water, the percentage of milk is 84%. How much water should be added so that the percentage of milk becomes 52.5% ? 95 litre 80 litre 85 litre 90 litre 95 litre 80 litre 85 litre 90 litre ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In 150 litre, milk is 84%ie 150 x 84/100 = 126 litre Let us add x litres of waterTherefore, the quantity of mixture = 150 + x∴ 52.5% of (150 + x) = 126 litres 150 + x = 126x100/52.5 = 240 litres∴ x = 240 - 150 = 90 litres
Number System If the sum of the two numbers is 22 and the sum of their squares is 404, then the product of the numbers is: 44 40 80 88 44 40 80 88 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the numbers be x and y. Then, (x + y) = 22 and x2 + y2 = 404 Now, 2xy = (x + y)2 - (x2 + y2) 2xy= 222 - 404 = 484 - 404 = 80xy = 40
Number System 36% of 850+? % of 592 = 750 75 12.5 25 50 75 12.5 25 50 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 75
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: 26 46 24 42 26 46 24 42 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 One half of a two digit number exceeds its one third by 6. What is the sum of the digits of the number? 5 9 3 7 5 9 3 7 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x/2 – x/3 = 6=> x =63 + 6 = 9
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