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A can do 1/2 of a piece of work in 5 days, B can do 3/5 of the same work in 9 days and C can do 2/3 of that work in 8 days. In how many days can three of them together do the work ?
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- 3 days
- 5 days
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4 1 days 2 - 4 days
Correct Option: D
Using basics of Rule 3,
| A can do | work in 5 days. | 2 |
∴ A can do 1 work in 10 days
Similarly,
| B can do 1 work in | × 9 = 15 days | 3 |
| C can do 1 work in 8 × | = 12 days. | 2 |
Now,
| A’s 1 day’s work = | 10 |
| B’s 1 day’s work = | 15 |
| C’s 1 day’s work = | 12 |
∴ (A + B + C)’s 1 day’s work
| = | + | + | ||||
| 10 | 15 | 12 |
| = | = | = | ||||
| 60 | 60 | 4 |
Hence, (A + B + C) together can complete the work in 4 days.
