Question: Swapnil can build a sofa in 16 days. Working together with Revathi he can finish the work in 129/17 days. Find the number of days taken by Revathi to complete the work if she works alone.
- 128/17 days
- 128/16 days
- 6 days
- 128/9 days
Answer: 4. 128/9 days
Solution:
building a sofa workdone = w
Swapnil can do in 16 days = w=16s
s=speed of swapnil
equation working together
(s+r)128/17=16s
r=(16s(17))/128 -s
r=1.125 s ( substituting s)
r=1.125 w/16
r (16)/1.125= w
r(14.22)=w
rt=w
t=128/9 days