Number System 4.78% of 1255 + 3.24% of 440=0.5% of ? 14849 12849 13849 11849 14849 12849 13849 11849 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 0.5 x ?/100 = 4.78 x 1255/100 + 3.24 x 440/100= 59.989 + 14.256∴ ? = 74.245 x 100/0.5 = 14849
Number System If A + B = 30 and AB = 94, What is the value of A² + B² ? 824 625 920 712 824 625 920 712 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (A + B)² = (30)² = 900A² + B² + 2AB = 900Therefore, A² + B² = 900 - 2 x 94 = 900 - 188 = 712
Number System The difference between 68% of a number and 35% of the same number is 1216. What is 28% of the number ? 1027.75 1031.75 1037.75 1043.75 1027.75 1031.75 1037.75 1043.75 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the no. be xTherefore 68x / 100 - 35x / 100 = 1216 Therefore x = 1216 x 100 / 33Therefore 28% of x = 28x / 100 = 1216 x 100 / 33 x 28 / 100= 1216 x 100 x 28 / 33 x 1/100 = 1031.75
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 ? 89/190 91/190 92/190 90/190 89/190 91/190 92/190 90/190 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 one-seventh of a number is 55 then 40% of that number = ? 147 163 154 171 147 163 154 171 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the no. be x , Therefore, x/7 = 55Therefore, x = 55 x 7 = 385Therefore, 49% of 385 = 154
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 42 24 26 46 42 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.
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