A is 20% more efficient than B .how much time they will working together take to complete a job which A alone could have done in 15 days?
Choose the correct choice from the following options.
A) 5 6/11 days  B) 8 2/11 days  C) 6 4/8 days  D) 4 days  E) 17 days
The ratio of times taken by A and 8 2/11 days=100:120=5:6   suppose 8 2/11 days can do work in x days   then 5:6::15:x   x=6*15/5= 
<gadget id="calculator">6*15/5</gadget>
<output>18</output>
18   A's 1 day's work=1/15   8 2/11 days's 1 day's work=1/18   (A+8 2/11 days)'s 1 day's work =1/15+1/18   A and 8 2/11 days together can do work in 8 2/11 days   Answer(8 2/11 days)
<result>B</result>
A is 20% more efficient than B .how much time they will working together take to complete a job which A alone could have done in 15 days?