Number System The difference between two integers is 5. Their product is 500. Find the numbers. 20, 25 21, 26 30, 25 15, 20 20, 25 21, 26 30, 25 15, 20 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the integers be x and (x + 5). Then, x(x + 5) = 500 x2 + 5x - 500 = 0 (x + 25)(x - 20) = 0 x = 20So, the numbers are 20 and 25.
Number System The product of two consecutive position odd numbers is 6723. What is the smaller number? 74 71 79 83 74 71 79 83 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 When (21)² is subtracted from the square of a number the answer obtained is 1584. What is the number ? 35 45 55 65 35 45 55 65 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.According to the question,x² - (21)² = 1584= x² - 441 = 1584 = x² = 1584 + 441 = 2025∴ x = √2025 = 45
Number System A box contains 5 red, 4 black and 4 blue balls. If 3 balls are drawn randomly from the box, what is the probability that there are exactly 2 blue balls in the three drawn balls ? 28/144 29/145 30/146 27/143 28/144 29/145 30/146 27/143 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Total balls = 5 + 4 + 4 = 13∴ n(S) = 13C3 = 2862 blue balls can be selected from 4 balls in 4C2 = 6 ways and the remaining one ball is to be selected from 9 balls in 9C1 = 9 ways ∴ n(E) = 6 x 9∴ P(E) = 6 x 9/286 = 27/143
Number System 4/6 of 6/5 of 5/7 of a number is 96. Find the number. 164 170 162 168 164 170 162 168 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.∴ x x 4/6 x 6/5 x 5/7 = 96∴ x = 96 x 6 x 5 x 7/4 x 6 x 5 = 168
Number System 5358 * 51 = ? 273268 273358 273258 273348 273268 273358 273258 273348 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 5358 * 51 = 5358 * (50 + 1) = 5358 * 50 + 5358 * 1= 267900 + 5358 = 273258
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