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: 81 18 42 24 81 18 42 24 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 sum of the digits of a two digit number is 12. If the new number formed by reversing the digits is greater than the original number by 54, then what will be the original number? 49 39 59 69 49 39 59 69 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 39
Number System What is the least number that should be added to 5200 to make it a perfect square ? 288 225 129 275 288 225 129 275 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP We sec (73)² = 5329 and (72)² = 5184ie 5329 > 5200 > 5184So 129 should be added to make is perfect square.
Number System On multiplying a number by 7, the product is a number each of whose digits is 3. The smallest such number is: 48619 47649 47719 47619 48619 47649 47719 47619 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP By hit and trail, we find that47619 * 7 = 333333.7) 333333 (47619 333333---------------- 0
Number System Find the number of factors of 300 excluding 1 and itself. 15 16 18 14 15 16 18 14 ANSWER DOWNLOAD EXAMIANS APP
Number System The average age of seven boys sitting in a row facing North is 26 years. If the average age of first three boys is 19 years and the average age of last three boys is 32 years, what is the age of the b 31 years 30 years 28 years 29 years 31 years 30 years 28 years 29 years ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Age of the fourth boy = (26 x 7 - 3 x 19 - 3 x 32) years = (182 - 57 - 96) years = 29 years
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