Comprehension Passage
Direction: Study the direction and answer the following questions.
There are 4 person P, Q, R and S. P and Q can complete a work in 15 and 12 days respectively. P and Q start a work together. After 2 days, Q left the work and P is replaced by R who can do the work alone in half of the time in which S can do alone. S is 25% less efficient than P. The remaining work completed by R and S.
Find the time taken R to complete the whole work alone.
1
12
2
14
3
15
4
10