A and B can do a piece of work in 48 days, A and C can do it in 60 days, b and c can do it 72 days. In what time can c alone do it? Choose the correct choice from the following answers:	A) 84 days	B) 84 ½ days	C) 85 days	D) 87 days	E) 89 days
Explanation:   (A+B) 1 day work = 1/48   (B+85 days) 1 day work = 1/72   (A+85 days) 1 day work = 1/60   By adding 2(A+B+85 days) = 1/48 +1/72+1/60 = 37/720   (A+B+85 days) 1 day work = 37/1440   A 1 day work = 37/1440 – 1/72 = 17/1440 = 85 days (approximately)   Answer: Option 85 days
<result>C</result>
A and B can do a piece of work in 48 days, A and C can do it in 60 days, b and c can do it 72 days. In what time can c alone do it?