A can do a piece of work in 10 days. He works at it for 4 days and then B finishes it in 9 days. In how many days can A and B together finish the work?
Choose the correct choice from the following options:	A) 6	B) 7	C) 5	D) 4	E) 1
4/10 + 9/x = 1 =&gt; x = 15   1/10 + 1/15 = 1/6 =&gt; 6 days   6nswer:6
<result>A</result>
A can do a piece of work in 10 days. He works at it for 4 days and then B finishes it in 9 days. In how many days can A and B together finish the work?