# A works twice as fast as B. If both of them can together finish a piece of work in 12 hours, then B alone can do it in  A. 24 hours

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A works twice as fast as B. If both of them can together finish a piece of work in 12 hours, then B alone can do it in

A. 24 hours

B. 27 hours

C. 36 hours

D. 18 hours

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Work done by A in one hour: 2x

Work done by B in one hour: x

Number of days taken by A and B to do the work together: 12 hours

Work done by A and B together in one hour: $\frac{1}{12}$

$\frac{1}{12}$ = 2x + x

$\frac{1}{12}$ = 3x

X = $\frac{1}{36}$

Here X is Work done by B in one hour

∴ B alone will take 36 hours to complete the work.