X can do a piece of work in 40days. He works at it for 8days and then Y finished it in 16days. How long will Y take to complete the work?  Choose the correct choice
A) 10 B) 12 C) 15 D) 18 E) 20
Work done by X in 8days = 8*1/40 = 1/5   Remaining work = 1 - 1/5 = 4/5   4/5 work is done by Y in 16days   Whole work will be done by Y in 16*5/4= 
<gadget id="calculator">16*5/4</gadget>
<output>20</output>
20days   Answer is 20
<result>E</result>
X can do a piece of work in 40days. He works at it for 8days and then Y finished it in 16days. How long will Y take to complete the work?