A is twice as good as B. And together they finish a piece of work in 20days. In how many days will A alone finish the work  Pick:
A) 30  B) 25  C) 12  D) 10  E) 32
(30's 1day work):(B's 1day work) = 2:1   30+B 1day work = 1/20   30's 1day work = (1/20)*(2/3) = 1/30   30 alone can finish the work in 30 days   30nswer is 30
<result>A</result>
A is twice as good as B. And together they finish a piece of work in 20days. In how many days will A alone finish the work