A can do a piece of work in 6 days. B is 25% more efficient than A. How long would B alone take to finish this work?

It is given that A takes 6 days to finish a work and it is also given that B is 25% more efficient than A ,it means that B will take less time to finish the work OR it can be said that :

B = 1.25 A

Using,

$$\frac{M1D1}{W1}$$ = $$\frac{M2D2}{W2}$$

D1 = 6 and D2 are the days taken by B to complete the work

Let the amount of work be , W1=W2=W

So,

$$\frac{A \times 6}{W}$$ = $$\frac{1.25 A \times D2}{W}$$

D2 = $$4\frac{4}{5}$$ days