A and B can do a piece of work in 10 days, B and C in 15 days, C and A in 12 days. How long will C take to do it?	Choose the correct choice from the following choices:	A) 70 days	B) 55 days	C) 24 days	D) 40 days	E) 11 days
2c = 1/15+ 1/12– 1/10 = 1/20   c = 1/40 =&gt; 40 days   Answer: 40 days
<result>D</result>
A and B can do a piece of work in 10 days, B and C in 15 days, C and A in 12 days. How long will C take to do it?