Ratio of time taken by P to Q to complete a work alone is 1 : 2 and time taken by P and Q together to complete the work is (40/3) days while the time taken by Q and R together to complete the work is 8 days, then what is the ratio of efficiency of person Q to that of R?
1
1 : 2
2
2 : 3
3
1 : 4
4
3 : 4