Question: A and B can do a job together in 7 days. A is 1 times as efficient as B. The same job can be done by A alone in :
[A].
11 days
[A].
| 9 | 1 | days |
| 3 |
[B].
[C].
| 12 | 1 | days |
| 4 |
[D].
| 16 | 1 | days |
| 3 |
Answer: Option B
Explanation:
| (A’s 1 day’s work) : (B’s 1 day’s work) = | 7 | : 1 = 7 : 4. |
| 4 |
Let A’s and B’s 1 day’s work be 7x and 4x respectively.
| Then, 7x + 4x = | 1 | 11x = | 1 | x = | 1 | . |
| 7 | 7 | 77 |
| A’s 1 day’s work = | 1 | x 7 | = | 1 | . | ||
| 77 | 11 |