Number System How many figures are required for numbering the pages of a book containing 1000 pages? 2893 6489 3892 2883 2893 6489 3892 2883 ANSWER DOWNLOAD EXAMIANS APP
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 ? 30/146 29/145 28/144 27/143 30/146 29/145 28/144 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 The sum of the numbers is 264. If the first number be twice the second and third number be one-third of the first, then the second number is: 48 72 84 54 48 72 84 54 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the second number be x. Then, first number = 2x and third number = 2x/3.2x + x + 2x/3 = 26411x/3 = 264x = 72
Number System Of an amount, 20% of 25% of 30% is Rs 75. Then what is the original amount ? Rs. 2000 Rs. 4000 Rs. 5000 Rs. 3000 Rs. 2000 Rs. 4000 Rs. 5000 Rs. 3000 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the amount be x.∴ X x 20/100 x 25/100 x 30/100 = 75∴ X = 75 x 5 x 4 x 10/3 = 5000
Number System What number should come in the place of (?) in the following number series ? 1, 4, 9, 25, 49, ?, 169, 289, 361 121 11 225 321 121 11 225 321 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP The series is (Prime No.)²So it is (11)² = 121
Number System If a + b = 16 and ab = 68, what is the value of a² + b² ? 112 116 120 124 112 116 120 124 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP a + b = 16 Therefore, (a+b)² = (16)² = 256 a² + b² + 2ab = 256Therefore, a² + b² = 256 - 2 x 68Therefore, a² + b² = 256 - 136 = 120
EXAMIANS