Number System The difference between a positive proper fraction and its reciprocal is 9/20. The fraction is: 3/10 3/5 4/5 5/4 3/10 3/5 4/5 5/4 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 1/x - x = 9/20 20x2 + 9x - 20 = 0 20x2 + 25x - 16x - 20 = 0 5x(4x + 5) -4(4x + 5) = 0(4x + 5)(5x - 4) = 0x = 4/5
Number System (√6 + 1)² = ? + 2√6 7 8 6 5 7 8 6 5 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? = (√6 + 1)² - 2√6= (√6)² + 2 x √6 + 1 + 1² - 2√6= 6 + 2√6 + 1 - 2√6 = 6 + 1 = 7
Number System In how many different ways can the letters of the word ANATOMY be arranged ? 2504 2508 2520 2510 2504 2508 2520 2510 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Here total letters are 7 but A comes twice.Therefore, Numbers of arrangements = 7!/2! = 2520
Number System What number should come in the place of (?) in the following number series ? 1, 4, 9, 25, 49, ?, 169, 289, 361 11 121 321 225 11 121 321 225 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP The series is (Prime No.)²So it is (11)² = 121
Number System 0.333 .... × 0.444 .... is equal to 0.121212 .... 1.333 .... 0.148148148 .... 0.777 .... 0.121212 .... 1.333 .... 0.148148148 .... 0.777 .... ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 0.148148148 ....
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 ? 91/190 92/190 90/190 89/190 91/190 92/190 90/190 89/190 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
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