Question 77

A can do a work in 24 days and B in 40 days. If they work on it together for 10 days, then what fraction of work is left?

Solution

Let the total work = LCM of 24 & 40 = 120 units

A's efficiency = 120/24 = 5

B's efficiency = 120/40 = 3

In 1day they can complete 8 units of work

In 10days they can complete 80 units of work

work left =120-80 = 40 units

fraction of work left = 40/120 = 1/3

So the answewr is option B.

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