Number System If the sum and difference of two numbers are 20 and 8 respectively, then the difference of their square is: 160 12 28 180 160 12 28 180 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the numbers be x and y. Then, x + y = 20 and x - y = 8x2 - y2 = (x + y)(x - y) = 20 * 8 = 160.
Number System What least number should be added to 8602 to make it a perfect square ? 51 36 41 47 51 36 41 47 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP So, (93)² = 8649So, the required number to be added to make a perfect square = 8649 - 8602 = 47
Number System A, B, C, D and E are consecutive even numbers respectively. The average of 5 numbers is 82. What is the product of C and E ? 6363 6373 6353 6383 6363 6373 6353 6383 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x + x + 1 + x + 2 + x + 3 + x + 4 = 5 x 82= 5x + 10 = 410 = 5x = 400= x = 400/5 = 80 ∴ A = 80C = 82and E = 84= C x E = 82 x 84 = 6383
Number System The average of 7 numbers is 15, that of the first three is 6 and that of the last three is 23. What is the fourth number? 7 18 15 13 7 18 15 13 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 4th No. = (Total of 7 Nos) - (Total of first three + total of last 3) = (15 x 7) - (6 x 3 + 23 x 3) = 105 - (18 + 69) =105 - 87 = 18
Number System A number consists of two digits. If 3/5 of 1/5 of the number is 9. Find the sum of its two digits? 12 8 7 60 12 8 7 60 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x * 3/5 * 1/5 = 9x = 75 => 7 + 5 = 12
Number System √(17)² + (17)² + (5)² - 2 = ? 16 18 17 19 16 18 17 19 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? = √49 + 289 + 25 - 2 = √361 = 19
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