Number System What is the missing number in this series? 8 2 14 6 11 ? 14 6 18 12 2 7 9 3 2 7 9 3 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 9
Number System (3² x 4² x 5) ÷ 36 = (?)² - 80 12 10 16 14 12 10 16 14 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (?)² = 3² x 4² x 5/36 + 80= 20 + 80 = 100∴ ? = √100 = 10
Number System If (83)² is subtracted from the square of a number, the answer so obtained is 8487. What is the number ? 163 146 179 124 163 146 179 124 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x Therefore, x² - (83)² = 8487x² = 8487 + (83)²x² = 8487 + 6889x² = 15376Therefore, x² = 15376 x = 124
Number System The product of two consecutive position odd numbers is 6723. What is the smaller number? 83 71 79 74 83 71 79 74 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP n x (n + 2) = 6723= n² + 2n - 6723 = 0= n² + 83n - 81n - 6723 = 0= n(n + 83) - 81 (n + 83) = 0Therefore, (n - 81) (n + 83) = 0Therefore, n = 81, n + 2 = 83
Number System An urn contains 9 blue, 7 white and 4 black balls. If 2 balls are drawn at random, then what is the probability that only one ball is white ? 89/190 90/190 92/190 91/190 89/190 90/190 92/190 91/190 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Total possible outcomes = 20C2 = 20 x 19/1 x 2 = 190Total favourable outcomes = 7C1 x 13C1 = 7 x 13 = 91∴ Required probability = 91/190
Number System If 35% of a number is 899.5, what is 68% of that number ? 1547.6 1847.6 1747.6 2247.6 1547.6 1847.6 1747.6 2247.6 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Suppose the number is x.Then 35% of x = 899.5∴ 68% of x = 68/35 x 899.5 = 1747.6
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