A and B together can do a work in 6 days. If A alone can do it in 15 days. In how many days can B alone do it?  Choose the most appropriate option.
A) 11	B) 10	C) 21	D) 20	E) 25
10   10   1/6 – 1/15 = 1/10 =&gt; 10
<result>B</result>
A and B together can do a work in 6 days. If A alone can do it in 15 days. In how many days can B alone do it?