Number System If (47)² is added to the square of a number the answer thus obtained is 2290. What is the number ? 8 10 7 9 8 10 7 9 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the no. be x Therefore, x² + (47)² = 2290Therefore, x² = 2290 - 2209 = 81Therefore, x = 9
Number System What is the least number that should be added to 5200 to make it a perfect square ? 275 225 129 288 275 225 129 288 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP We sec (73)² = 5329 and (72)² = 5184ie 5329 > 5200 > 5184So 129 should be added to make is perfect square.
Number System In a two-digit number, the digit in unit's place is two more than three times the digit in ten's place. If the sum of the two digits is 10, what is the number ? 18 22 28 24 18 22 28 24 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be 10x + y.∴ y = 3x + 2 .......(i)And, x + y = 10 ......(ii)From (i) and (ii), x = 2, y = 8∴ Number = 28
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: 84 72 54 48 84 72 54 48 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 The product of two successive numbers is 4556. Which of the following is the larger of the two numbers? 63 67 78 68 63 67 78 68 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
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