Correct Option: A
| (A+B)’s 1 day’s work = | 1 | |
| 10 |
| (B + C)’s 1 day’s work = | 1 | |
| 12 |
| (C + A)’s 1 day’s work = | 1 | |
| 15 |
On adding all three,
| 2(A + B + C)’s 1 day’s work = | 1 | + | 1 | + | 1 |
10 | 12 | 15 |
| 2(A + B + C)’s 1 day’s work = | 6 + 5 + 4 | |
| 60 |
| 2(A + B + C)’s 1 day’s work = | 15 | = | 1 | |
60 | 4 |
| ∴ (A + B + C)’s 1 day’s work = | 1 | |
| 8 |
| ∴ A’s 1 day’s work = | 1 | - | 1 | |
8 | 12 |
| A’s 1 day’s work = | 3 - 2 | = | 1 | |
24 | 24 |
∴ A will complete the work in 24 days.
Second method to solve this question ,Here , x = 10 , y = 12 , z = 15
| A alone can do in = | 2 × x × y × z | |
| xy + yz + zx |
| A alone can do in = | 2 × 10 × 12 × 15 | |
| 10 × 12 + 12 × 15 - 15 × 10 |
| A alone can do in = | 3600 | |
| 120 + 180 - 150 |
| A alone can do in = | 3600 | = 24 days |
| 150 |
