A is thrice as efficient as B and is, therefore, able to finish a piece of work 10 days earlier than B. In how many days A and B will finish it together? Choose the correct choice from the following
A) 62  B) 78  C) 23  D) 5  E) 32
WC = 3:1   WT = 1:3   x 3x   1/x – 1/3x = 1/10   x = 20/3   3/20 + 1/20 = 1/5 =&gt; 5 days   Answer: 5
<result>D</result>
A is thrice as efficient as B and is, therefore, able to finish a piece of work 10 days earlier than B. In how many days A and B will finish it together?