InterviewSolution
Saved Bookmarks
| 1. |
If N = 123 × 34 × 52 , then the total number of even factors of N is (a) 25 (b) 121 (c) 144 (d) 84 |
|
Answer» (c) 144 N = (22 × 3)3 × 34 × 52 = 26 × 37 × 52 \(\therefore\) Total number of factors of N = (6 + 1) × (7 + 1) × (2 + 1) = 7 × 8 × 3 = 168 Some of these are odd factors and some of these are even factors. The odd factors are formed with the combination of 3s and 5s. \(\therefore\) Total number of odd factors = ( 7 + 1) × (2 +1) = 8 + 3 = 24 \(\therefore\) Number of even factors = 168 – 24 = 144. |
|