P can do a work in 60 days. Q can do the same work in 9 days and R can do the same in 12 days. Q and R start the work and leave after 3 days. P finishes the remaining work in --- days.  Choose one.
A) 7  B) 8  C) 9  D) 15  E) 25
Work done by P in 1 day = 1/60   Work done by Q in 1 day = 1/9   Work done by R in 1 day = 1/12   Work done by Q and R in 1 day = 1/9 + 1/12 = 7/36   Work done by Q and R in 3 days = 3Ã—7/36 = 7/12   Remaining work = 1 â€“ 7/12 = 5/12   Number of days in which P can finish the remaining work = (5/12) / (1/60)= 
<gadget id="calculator">(5/12) / (1/60)</gadget>
<output>25</output>
25   Option 25
<result>E</result>
P can do a work in 60 days. Q can do the same work in 9 days and R can do the same in 12 days. Q and R start the work and leave after 3 days. P finishes the remaining work in --- days.