Question:
A can do a certain work in the same time in which B and C together can do it. If A and B together could do it in 10 days and C alone in 50 days, then B alone could do it in:
[A].15 days
20 days
25 days
30 days
A can do a certain work in the same time in which B and C together can do it. If A and B together could do it in 10 days and C alone in 50 days, then B alone could do it in:
[A].
[B].
[C].
[D].
Answer: Option C
Explanation:
| (A + B)’s 1 day’s work = | 1 |
| 10 |
| C’s 1 day’s work = | 1 |
| 50 |
| (A + B + C)’s 1 day’s work = | 1 | + | 1 | = | 6 | = | 3 | . …. (i) | ||
| 10 | 50 | 50 | 25 |
A’s 1 day’s work = (B + C)’s 1 day’s work …. (ii)
| From (i) and (ii), we get: 2 x (A’s 1 day’s work) = | 3 |
| 25 |
| A’s 1 day’s work = | 3 | . |
| 50 |
| B’s 1 day’s work | 1 | – | 3 | = | 2 | = | 1 | . | ||
| 10 | 50 | 50 | 25 |
So, B alone could do the work in 25 days.