Number System If (72)² is subtracted from the square of a number, the answer thus obtained is 4617. What is the number ? 103 95 99 92 103 95 99 92 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x² - (72)² = 467Therefore, x² = 4617 + 5184Therefore, x² = 9801 Therefore, x = 99
Number System 480% of 350 + 620% of 275 = ? 2385 5385 4385 3385 2385 5385 4385 3385 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? = 480 x 350/100 + 620 x 275/100= 1680 + 1705 = 3385
Number System Sum of square of first number and cube of second number together is 568. Also square of the second number is 15 less than square of 8. What is the value of three-fifth of the first number ? 6 7 8 9 6 7 8 9 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the first number be x and the second number be y.∴ y² = 82 - 15 = 64 - 15 = 49∴ y = 7∴ x² + 73 = 568= x² + 343 = 568= x² + 568 - 343 = 225∴ x = √225 = 15∴ 15 x 3/5 = 9
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 90/190 91/190 92/190 89/190 90/190 91/190 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 In a two-digit number, the digit in unit's place is two more than three times the digit in ten's place. If the sum of the two digits is 10, what is the number ? 28 24 22 18 28 24 22 18 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be 10x + y.∴ y = 3x + 2 .......(i)And, x + y = 10 ......(ii)From (i) and (ii), x = 2, y = 8∴ Number = 28
Number System 1089/? = ?/1296 1348 1082 1278 1188 1348 1082 1278 1188 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (?)² = 1089 x 1296(?)²= (11 x 11 x 9) x (12 x 12 x 9)(?)= 11 x 12 x 9= 1188
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