Number System In how many different ways can the letters of word 'BIOLOGY' be arranged ? 2520 2410 2367 2678 2520 2410 2367 2678 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In BIOLOGY total 7 letters are there but O comes twice.∴ Number of arrangements = 7!/2! = 2520
Number System The product of two consecutive odd numbers is 6723. Find is the greater number. 80 83 85 77 80 83 85 77 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the first odd number be x.Then, the other odd number would be x + 2.∴ x(x+2) = 6723= x2 + 2x = 6723= x2 + 2x = 6723= x2 + 2x - 6723 = 0= x2 + 83 - 81 x - 6723 = 0= x(x+83) - 81 (x + 83) = 0= (x + 83) (x - 81) = 0= (x + 83) (x - 81) = 0= x - 81 = 0∴ x = 81Hence, greater number = x + 2 = 81 + 2 = 83
Number System A two-digit number is such that the product of the digits is 8. When 18 is added to the number, then the digits are reversed. The number is: 42 81 24 18 42 81 24 18 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the ten's and unit's digit be x and 8/x respectively. Then, (10x + 8/x) + 18 = 10 * 8/x + x 9x2 + 18x - 72 = 0 x2 + 2x - 8 = 0 (x + 4)(x - 2) = 0 x = 2 So, ten's digit = 2 and unit's digit = 4. Hence, required number = 24.
Number System The difference between 45% of a number and 18% of the same number is 145.8. What is 30% of that number ? 188 141 162 245 188 141 162 245 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.45% of x - 18% of x = 145.8∴ x/100 (45 - 18) = 145.8∴ x = 145.8 x 100/27 = 540∴ 30% of 540 = 540 x 30/100 = 162
Number System If the fractions 1/7, 3/5, 2/5, 5/6 and 9/11 are arranged in descending order of their values, which one will be the fourth number? 3/5 1/5 4/5 2/5 3/5 1/5 4/5 2/5 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 1/4 = 14. 3/5 = 6.2/5 = 4.5/6 = 83.9/11 = 82.Therefore, 83 > 82 > 6 > 14
Number System {3√4913}² = ? 333 225 289 121 333 225 289 121 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? = (3√4913)² = (17)² = 289
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