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Question
A and B take 6 hours and 9 hours respectively to complete a work. A works for 1 hour and then B works for two hours.
(i) How much work is done in these 3 hours?
(ii) How much work is still left?
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Solution
A takes 6 hours to finish work
and B take 9 hours to finish the same work
∴ A's 1 hour's work = `1/6`
and B's 1 hour's work = `1/9`
and B's 2 hours work =`1/9 xx 2= 2/9`
(i) Now A's 1 hours work + B's 2 hours work
`= 1/6 + 2/9 = (3 + 4)/18 = 7/18`
(ii) Work left = `1 - 7/18 = (18 - 7)/18 = 11/18`
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