A and B can do a work in 6 days.They both started the work and after three days A left the work.B finished the remaining work in 15 days.In how many days will A finish the work?  Select:
A) 7 days
B) 7.5 days
C) 8.5 days
D) 9.5 days
E) 6.5 days
A and B'S 1 DAY WORK i.e A+B =1/6   WORK COMPLETED AFTER THREE DAYS=3*1/6=1/2   REMAINING WORK 1/2 i.e 50 percentage completed by B in 15 days,so B can finish work in 30 days.. b's 1 day work 1/30   a's 1 day work=1/6-1/30=4/30   so a can finish work 30/4= 
<gadget id="calculator">30/4</gadget>
<output>15/2 = around 7.5</output>
7.5 days   ANSWER:7.5 days
<result>B</result>
A and B can do a work in 6 days.They both started the work and after three days A left the work.B finished the remaining work in 15 days.In how many days will A finish the work?