Problema Solution

A and B can finish a work in 30 days. They worked for it for 20 days and then B left. The remaining work was done by A alone in 20 more days. How many days will A take to finish the work alone?

Answer provided by our tutors

Let 'a' and 'b' stand for the rates of A and B in jobs/day. We will use the general equation (#of jobs done)=(rate)*(time). We can write:


1=(a+b)30

1=(a+b)20+a20


what is a?


Using Algebrator to solve for 'a' and 'b', we get:


a= 1/60 jobs/days


Therefore, it would take A 60 days to do the job alone.