P alone can do a work in 20 days and Q alone in 30 days. R alone can do work in 60 days. They take Rs. 12000 to complete the work. If P and Q took help of R to complete the work, then what is the difference in share of Q and R?
1
Rs. 1000
2
Rs. 1250
3
Rs. 2000
4
Rs. 4000