A and B can compete a piece of work in 18 days. They worked together for 12 days and then A left. B alone finished the work in 15 days. If Rs. 1500 be paid for the work then A's share is:
A. Rs. 750
B. Rs. 800
C. Rs. 600
D. Rs. 900
Answer: Option C
A. Rs. 750
B. Rs. 800
C. Rs. 600
D. Rs. 900
Answer: Option C
A. 18 days
B. 24 days
C. 30 days
D. 40 days
Let the total work be: 1 unit
A + B can do it in 1/18 units/day
so, In 12 days A + B together finish = 12/18 units/day
Remaining work for B to do it alone is = 1 - 12/18 = 6/18 units/day
In the next 15 days B alone does this 6/18 units/day amount of work.
so, in 1 day B does = (6/18 * 1/15) units/day amount of work.
Now B in total works for 27 days.
Total work done by B = 27 * 6/18 * 1/15 units = 3/5 units.
and A does 1 - 3/5 units which is 2/5 units.
hence the share of A is 2/5 * 1500 = Rs 600(Answer)
Xpln it plz??