Question

A and b can do a work in 15 ans 20 days find the work done by a in 3 days

Answer 1

Answer:

Step-by-step explanation:

A completes a work in 15 days

A --> 15 days= 1 work

-----> 1 day = 1/15 work

-----> 3 days =3*(1/15)work=1/5work

A takes 3 days to complete (1/5)the of work

B completes a work in 20 days

B---> 20days=1 work

-----> 1 day = 1/20 work

-----> 3 days = 3/20 work

B takes 3 days to complete (3/20)the of work

If together A+B is asked to complete a work,

( Here, let work be denoted as W)

A+B---> 1 day = (1/15)W+(1/20)W= 7/60 W

(Since 60 is L.C.M)

A+B----> 3 days = 3 * (7/60)W

= 7/20W

A and B together takes 3 days to complete (7/20)the of work.