Number System A basket contains 5 blue, 4 green and 3 red ball. If three balls are picked at random, what is the probability that at least one is red ? 32/51 31/58 37/52 34/55 32/51 31/58 37/52 34/55 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Probability of having no red ball is9C3 / 12C3 = 21/55Probability of having at least one red ball is 1 - 21/55 = 34/55
Number System When the square of a number is substracted from (68)², the answer so obtained is 2508. What is the number ? 45 46 47 44 45 46 47 44 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (68)² - x² = 2508Therefore, x² = 4624 = 2508Therefore, x = root of 2116 = 46
Number System If (35)² is added to the square of a number the answer so obtained is 1394. What is the number ? 15 11 13 17 15 11 13 17 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x Therefore, x² + (35)² = 1394Therefore, x² = 1394 - (35)² = 1394 - 1225 = 169Therefore, x = √169 = 13
Number System If one third of 3/4 of a number is 21. Then find the number? 84 63 840 630 84 63 840 630 ANSWER DOWNLOAD EXAMIANS APP
Number System A certain number of two digits is three times the sum of its digits. If 45 be added to it, the digits are reversed. The number is: 30 24 27 22 30 24 27 22 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 27
Number System Pick the wrong number from the given number series. 3,4,10,33,135,685,4116 10 33 135 685 10 33 135 685 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP The correct number is 136.3 x 1 + 1 = 44 x 2 + 2 = 1010 x 3 + 3 = 3333 x 4 + 4 = 136136 x 5 + 5 = 685685 x 6 + 6 = 4116