Number System In how many different ways can the letters of word 'BIOLOGY' be arranged ? 2520 2410 2367 2678 2520 2410 2367 2678 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In BIOLOGY total 7 letters are there but O comes twice.∴ Number of arrangements = 7!/2! = 2520
Number System If (74)² is added to the square of a number the answer so obtained is 7780. What is the number ? 48 50 47 49 48 50 47 49 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.or, x² + (74)² = 7780or, x² = 7780 - 5476 = 2304∴ x = 48
Number System If (72)² is subtracted from the square of a number, the answer thus obtained is 4617. What is the number ? 95 99 103 92 95 99 103 92 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x² - (72)² = 467Therefore, x² = 4617 + 5184Therefore, x² = 9801 Therefore, x = 99
Number System The difference between a number and its three-fifth is 50. What is the number? 100 75 125 None of these 100 75 125 None of these ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x - 3/5 x = 50 => 2/5 x = 50x = (50 * 5)/2 = 125.
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 92/190 91/190 90/190 89/190 92/190 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 5358 * 51 = ? 273268 273348 273358 273258 273268 273348 273358 273258 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 5358 * 51 = 5358 * (50 + 1) = 5358 * 50 + 5358 * 1= 267900 + 5358 = 273258
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