X can finish a work in 30 days. Y can finish the same work in 15 days. Yworked for 10 days and left the job. how many days does X alone need to finish the remaining work?  Answers:
A) 3  B) 10  C) 6  D) 8  E) 9
Work done by X in 1 day = 1/30   Work done by Y in 1 day = 1/15   Work done by Y in 10 days = 10/15 = 2/3   Remaining work = 1 – 2/3 = 1/3   Number of days in which X can finish the remaining work = (1/3) / (1/30)= 
<gadget id="calculator">(1/3) / (1/30)</gadget>
<output>10</output>
10   10
<result>B</result>
X can finish a work in 30 days. Y can finish the same work in 15 days. Yworked for 10 days and left the job. how many days does X alone need to finish the remaining work?