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 Of the three numbers, second is twice the first and is also thrice the third. If the average of the three numbers is 44, the largest number is 44 72 56 38 44 72 56 38 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 72
Number System What is the value of ? in the following equations ? 72/? = ?/50 80 60 40 100 80 60 40 100 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (?)² = 72 x 50= (6 x 6 x 2) x (5 x 5 x 2)= (6 x 5 x 2)² = (60)²∴ ? = 60
Number System How many numbers up to 100 are divisible by 7? 100 14 93 107 100 14 93 107 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 100/7 = 14 2/7 => 14 Numbers
Number System (12.04 x 7.5 + 0.8 x 45) ÷ 3 = ? 42.6 54.7 42.1 45 42.6 54.7 42.1 45 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (90.3 + 36) ÷ 3 = 126.3/3 = 42.1
Number System The difference between 45% of a number and 18% of the same number is 145.8. What is 30% of that number ? 245 162 188 141 245 162 188 141 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.45% of x - 18% of x = 145.8∴ x/100 (45 - 18) = 145.8∴ x = 145.8 x 100/27 = 540∴ 30% of 540 = 540 x 30/100 = 162
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