A can lay railway track between two given stations in 16 days and B can do the same job in 12 days. With help of C, they did the job in 4 days only. Then, C alone can do the job in:	Choose one.
A) 9 1/5 days	B) 9 3/5 days	C) 9 2/5 days	D) 10 days	E) 10 1/5 days
(A + B + C)'s 1 day's work =1/4   A's 1 day's work =1/16   B's 1 day's work =1/12   Therefore C's 1 day's work =1/4-(1/16+1/12)=(1/4-7/48)=5/48	.   So, C alone can do the work in	48/5= 9 3/5days.   Option 9 3/5 days
<result>B</result>
A can lay railway track between two given stations in 16 days and B can do the same job in 12 days. With help of C, they did the job in 4 days only. Then, C alone can do the job in: