Question

11. A, B and C can do a piece of work in 15, 12 and 20 days respectively. They started the work
together, but C left after 2 days. In how many days will the remaining work be completed by
A and B?​

Answer 1

let

A time =

$1 \div 15$

B time =

$1 \div12$

and

c time=

$1 \div 20$

together their work=

=1/15+1/12+1/20

= 1/5

c left =1/5-1/20

v. =3/20

time = 20/3