Mary can do a piece of work in 12 days. Rosy is 50% more efficient than Mary. The number of days taken by Rosy to do the same piece of work is?	Choose the most appropriate option.
A) 7	B) 8	C) 9	D) 11	E) 10
Ratio of times taken by Mary and Rosy = 150:100 = 3:2   Suppose Rosy takes x days to do the work.   3:2 :: 12:x =&gt; x= 8 days.   Hence, Rosy takes 8 days to complete the work.   Answer: 8
<result>B</result>
Mary can do a piece of work in 12 days. Rosy is 50% more efficient than Mary. The number of days taken by Rosy to do the same piece of work is?