Number System What is the sum of 1 + 2 + 3+ ... + 27 ? 396 378 382 343 396 378 382 343 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Sum = 27 x (27 + 1)/2= 27 x 28/2= 27 x 14= 378
Number System The sum of five consecutive numbers is 190. What is the sum of the largest and the smallest number ? 75 74 76 73 75 74 76 73 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP x + x + 1 + x + 2 + x + 3 + x + 4= 190= 5x + 10 = 190= 5x = 190 - 10 = 180= x = 180/5 = 36The largest number = 36 + 4 = 40∴ Required sum = 36 + 40 = 76
Number System In how many different ways can the letters of word 'BIOLOGY' be arranged ? 2678 2410 2520 2367 2678 2410 2520 2367 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In BIOLOGY total 7 letters are there but O comes twice.∴ Number of arrangements = 7!/2! = 2520
Number System On dividing 2272 as well as 875 by 3-digit number N, we get the same remainder. The sum of the digits of N is: 10 13 11 12 10 13 11 12 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Clearly, (2272 - 875) = 1397, is exactly divisible by N.Now. 1397 = 11 * 127The required 3-digit number is 127, the sum of whose digit is 10.
Number System The sum of three consecutive even numbers is 252. What is the sum of the smallest and the largest numbers? 168 171 170 169 168 171 170 169 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 168
Number System The product of two consecutive position odd numbers is 6723. What is the smaller number? 79 74 83 71 79 74 83 71 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
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