Question

A is thrice as efficient as B and hence complete a work in 40 days less than the number of days taken by b.what is the number of days taken by both of then when work together

Answer 1

work of B in 1 hr be X
work of A in 1hr is 3X
$no \: days \: taken \: by \: b = \frac{1}{x} \\ \: no \: days \: taken \: by \: a = \frac{1}{3x}$
$\frac{1}{x} - \frac{1}{3x} = \frac{3 - 1}{3x} = \frac{2}{3x}$
$\frac{2}{3x} = 40 \\ x = \frac{2}{3 \times 40} = \frac{1}{60}$

3x=(1/20)
total work done in 1 hr =(1/20)+(1/60)=(3+1)/60
=2/60
=1/30
no of days taken when whorking togeather=30