A can do a work in 7 days. B is 20% more efficient than A. How many days does B alone take to do the same job?  Choose the correct choice from the following choices.
A) 28/6 B) 25/6 C) 35/6 D) 33/6 E) 39/6
Ratio of times taken by A and B = 120:100 = 6:5   suppose B alone to take x days to do the work   then, 6:5::7:x   6x= 5*7= 
<gadget id="calculator">5*7</gadget>
<output>35</output>
35/6 days   correct option is 35/6
<result>C</result>
A can do a work in 7 days. B is 20% more efficient than A. How many days does B alone take to do the same job?