Number System The difference between 71% of a number and 46% and of the same number is 212. What is 75% of that number 845 724 673 636 845 724 673 636 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 What is the least number, which is perfect square but contains 2700 as its factor? 10800 1800 5400 2700 10800 1800 5400 2700 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 900 * 3 * 3 = 8100
Number System In a five-litre mixture of milk and water the portion of water is 30%. How much milk should be added to the mixture so that the portion of water reduces to 5% ? 17 litre 29 litre 25 litre 21 litre 17 litre 29 litre 25 litre 21 litre ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Original mixture = 5 litre; Milk = 3.5 litre;Water = 1.5 litre Let x litre of milk be added so thatthe mixture becomes (x + 5) litres and the percentage of water becomes 5%So, 1.5 = (x + 5) x 5/10030 = x + 5∴ x = 25 litre
Number System An urn contains 9 blue, 7 white and 4 black balls. If 2 balls are drawn at random, then what is the probability that only one ball is white ? 90/190 91/190 89/190 92/190 90/190 91/190 89/190 92/190 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Total possible outcomes = 20C2 = 20 x 19/1 x 2 = 190Total favourable outcomes = 7C1 x 13C1 = 7 x 13 = 91∴ Required probability = 91/190
Number System If 5/7 of a number is 145, what is 180% of that number ? 355.4 345.4 365.4 375.4 355.4 345.4 365.4 375.4 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.∴ x x 5/7 = 145∴ x = 145 x 7/5 = 203Now, 203 x 180/100 = 365.4
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: 80 40 88 44 80 40 88 44 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
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