4 men and 12 boys finish a piece of work in 4 days, 7 men and 6 boys do it in 5 days. The ratio between the efficiencies of a man and boy is?	Options:
A) 18:19
B) 17:19
C) 15:19
D) 18:14
E) 18:11
4M + 12B ----- 4 days   7M + 6B ------- 5 days   16M + 48B = 35M + 30B   18B = 19M =&gt; 5M = 6B   M: B = 18:19   18:19NSWER:18:19
<result>A</result>
4 men and 12 boys finish a piece of work in 4 days, 7 men and 6 boys do it in 5 days. The ratio between the efficiencies of a man and boy is?