Question 54

A is twice as good as a workman as B. And together, they finish a piece of work in 20 days. In how many days, will A alone finish the work?

Solution

Let B take x days to do a job

Then A takes $$\frac{x}{2}$$ days

Per day they work together $$\frac{1}{x}+\frac{2}{x} =\frac{3}{x} $$

In 20 days they do $$\frac{x}{(3\times 20)} $$ of work

$$\frac{60}{x}$$=1

x=60

A takes $$\frac{60}{2}=30 $$days

Option A is correct.

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