Number System A two-digit number is such that the product of the digits is 8. When 18 is added to the number, then the digits are reversed. The number is: 42 81 24 18 42 81 24 18 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the ten's and unit's digit be x and 8/x respectively. Then, (10x + 8/x) + 18 = 10 * 8/x + x 9x2 + 18x - 72 = 0 x2 + 2x - 8 = 0 (x + 4)(x - 2) = 0 x = 2 So, ten's digit = 2 and unit's digit = 4. Hence, required number = 24.
Number System The product of two natural numbers is 17. Then, the sum of the reciprocals of their squares is: 290/289 1/289 289 289/290 290/289 1/289 289 289/290 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the numbers be a and b. Then,ab = 17, a = 1 and b = 17So, 1/a2 + 1/b2 = (a2 + b2)/a2 b2 = (12 + 172)/(1 * 17)2 = 290/289
Number System In how many different ways can the letters of the word ANATOMY be arranged ? 2504 2510 2508 2520 2504 2510 2508 2520 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Here total letters are 7 but A comes twice.Therefore, Numbers of arrangements = 7!/2! = 2520
Number System What is the sum of all the prime numbers from 20 to 40? 118 120 117 119 118 120 117 119 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 23 + 29 + 31 + 37 = 120
Number System (12.11)2 + (?)2 = 732.2921 14.2 24.2 20.2 17.2 14.2 24.2 20.2 17.2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 24.2
Number System 56.21 +2.36+5.41 —21.4+1.5=? 34.08 64.08 44.08 54.08 34.08 64.08 44.08 54.08 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 44.08
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