Number System On multiplying a number by 7, the product is a number each of whose digits is 3. The smallest such number is: 47719 47649 47619 48619 47719 47649 47619 48619 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP By hit and trail, we find that47619 * 7 = 333333.7) 333333 (47619 333333---------------- 0
Number System (3² x 4² x 5) ÷ 36 = (?)² - 80 14 16 10 12 14 16 10 12 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (?)² = 3² x 4² x 5/36 + 80= 20 + 80 = 100∴ ? = √100 = 10
Number System If x + y = 61 and xy = 888, What is the value of x²+ y² ? 1975 1955 1945 1965 1975 1955 1945 1965 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Because (x + y)² = x² + y² + 2xy∴ x² + y² = (x + y)² - 2xy∴ x² + y² = (61)² - 2 x 888= 3721 - 1776 = 1945
Number System What least number should be added to 8602 to make it a perfect square ? 41 47 51 36 41 47 51 36 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 What value should come in place of ? in the given number series ? 15, 51, 162, 498, 1509, ? 5656 7878 4545 3434 5656 7878 4545 3434 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 15, (15 + 2) x 3 = 51,(51 + 3) x 3 = 162, (162 + 4) x 3 = 498, (498 + 5) x 3 = 1509(1509 + 6) x 3 = 4545
Number System 17580 x 1.8 - 13720 x 2.1 = ? x 2.4 1140 1120 1180 1160 1140 1120 1180 1160 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 2.4 x ? = 31644 - 28812 = 2832∴ ? = 2832/2.4= 1180
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