Question

A and b can do a piece of work in 16 days and 25 days respectively. If they work on alternate days starting with , then in how many days the work will be completed

Answer 1

$a \: works \: in \: one \: day = \frac{1}{16} \\ b \: works \: in \: one \: day = \frac{1}{25} \\ both \: together \: works \: in \: one \: day = \frac{1}{16} + \frac{1}{25} = \frac{41}{400} \\ both \: together \: complete \: the \: work = 1 \div \frac{41}{400} \\ = \frac{400}{41} days$