The ratio of the efficiencies of A, B and C is 7 ∶ 5 ∶ 4. Working together, they can finish a work in 35 days. A and B work together for 28 days. The remaining work will be completed (in days) by C alone∶

The ratio of the efficiencies of A, B and C is 7 ∶ 5 ∶ 4. Working

1.	The ratio of the efficiencies of A, B and C is 7 ∶ 5 ∶ 4. Working together, they can finish a work in 35 days. A and B work together for 28 days. The remaining work will be completed (in days) by C alone∶
A.	49
B.	56
C.	63
D.	60
Answer» C. 63