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 ? 92/190 89/190 91/190 90/190 92/190 89/190 91/190 90/190 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 The sum of the digits of a two-digit number is 12, and the difference between the number and the number obtained by interchanging the two digits of the number is 18. Find the number. 50 12.5 25 75 50 12.5 25 75 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be 10x + y.∴ x + y = 12 ...........(i)10x + y - (10x + x) = 18or 10x + y - 10y - x = 18or 9x - 9y = 18∴ x - y = 2From (i) and (ii), x = 7, y = 5∴ Number = 75
Number System Subtracting 30 from a number, the remainder is one fourth of the number. Find the number? 45 30 22 1/2 40 45 30 22 1/2 40 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 3/4 x = 30 => x = 40
Number System Sum of two numbers is 80. Greater number exceeds by 5 from four times of the smaller. Find the numbers? 62, 18 65, 15 64, 16 60, 20 62, 18 65, 15 64, 16 60, 20 ANSWER DOWNLOAD EXAMIANS APP
Number System What number should replace both the question marks (?) in the following question ? 85 84 82 83 85 84 82 83 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 84
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