A and B can do a job together in 7 days. A is 1 times as efficient as B. The same job can be done by A alone in :

A and B can do a job together in 7 days. A is 1 times as efficient as

1.	A and B can do a job together in 7 days. A is 1 times as efficient as B. The same job can be done by A alone in :
A.	9 1 days 3
B.	11 days
C.	12 1 days 4
D.	16 1 days 3
Answer» C. 12 1 days 4