Question

A can do a piece of work in 10 days, and B can do the same work in 20 days. With the help of C, they finished the work in 4 days. C can do the work in how many days, working alone?
1. 5 days
2. 10 days
3. 15 days
4. 20 days
5. 25 days​

Answer 1

Answer:

A can do a piece of work in 10 days, and B can do the same work in 20 days. With the help of C, they finished the work in 4 days. C can do the work in how many days, working alone? Explanation:Their combined 4 day work = 4(1/10 + 1/15) = 12/20 = 3/5.