Question

A can do a piece of work in 14 days while B can do in 21 days they begin together but three days before the completion of the work A leaves off find the total number of days taken to complete the work

Answer 1

let us consider that work is done in x days then
work of a is x-3/14
work of b is x/21
equation formes is
x-3/14+x/21=1 further solving it
we get x=51/5 days