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प्रश्न
A can do a piece of work in 4 days and B can do the same work in 5 days. Find, how much work can be done by them working together in:
- one day
- 2 days
What part of work will be left, after they have worked together for 2 days?
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उत्तर
A can do a piece of work in 4 days
and B can do the same work in 5 days
∴ A's one day's work = `1/4`
and B;s one day's work = `1/5`
(i) A and B's both one day's work = `1/4 + 1/5`
`= (5 + 4)/20 = 9/20`
(ii) A and B's 2 day's work `= 9/20 xx 2 = 9/10`
∴ work left after 2 day's = `1 - 9/10`
`= (10 - 9)/10 = 1/10`
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