4 male farmers and 6 female farmers can cultivate a field in 8 days, while 3 male farmers and 7 female farmers can cultivate the field in 10 days. In how many days 10 female farmers can cultivate the same field?
Choices:
A) 10
B) 20
C) 30
D) 40
E) 50
WORK DONE IN 1 DAY   4M+6F=1/8   3M+7F=1/10   SOLVING THIS WE GET F=1/400   SO IN 10 DAYS,WORK DONE IS 10/400,hence female farmers take 40 days to complete the work.   ANSWER:40
<result>D</result>
4 male farmers and 6 female farmers can cultivate a field in 8 days, while 3 male farmers and 7 female farmers can cultivate the field in 10 days. In how many days 10 female farmers can cultivate the same field?