Number System What is the sum of 1 + 2 + 3+ ... + 27 ? 396 343 378 382 396 343 378 382 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Sum = 27 x (27 + 1)/2= 27 x 28/2= 27 x 14= 378
Number System The difference between a two-digit number and the number obtained by interchanging its two digits is 45. The sum of the digit of the number is 9. What is the product of the two digits of the number? 15 12 14 13 15 12 14 13 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be 10x + y.Therefore, x + y = 9 ..................(i)10x + y - (10y + x) = 4510x + y - 10y - x = 45Therefore, x - y = 5 ..................(ii)From (i) and (ii), x = 7, y = 2Number = 72Therefore, = x x y = 7 x 2 = 14
Number System What is the sum of all even numbers from 1 to 701? 122500 122850 123850 122550 122500 122850 123850 122550 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 700/2 = 350350 * 351 = 122850
Number System If A + B = 30 and AB = 94, What is the value of A² + B² ? 712 625 920 824 712 625 920 824 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (A + B)² = (30)² = 900A² + B² + 2AB = 900Therefore, A² + B² = 900 - 2 x 94 = 900 - 188 = 712
Number System Which is the largest fraction among the following ? 12/13 21/23 21/22 24/25 12/13 21/23 21/22 24/25 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 21/23 = 0.913,12/13 = 0.92323/25 = 0.92, 21/22 = 0.9545, 24/25 = 0.96
Number System In how many ways can 5 boys be chosen from 6 boys and 4 girls so as to include exactly one girl ? 60 58 54 56 60 58 54 56 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP One girl can be chosen in 4C1 = 4 ways and 4 boys can be chosen in 6C4 = 15 ways ∴ Total number of ways = 4 x 15 = 60 ways.
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