A is half good a work man as B and together they finish a job in 10 days. In how many days working alone B finish the job?  Pick:
A) 23
B) 22
C) 15
D) 36
E) 48
15   15   W15 = 1:2   2x + x = 1/10 =&gt; x = 1/30   2x = 1/15 =&gt; 15 days
<result>C</result>
A is half good a work man as B and together they finish a job in 10 days. In how many days working alone B finish the job?