Before a salary hike, the weekly salary of a worker for 40 hours in a week was as much as he is paid now for 35 hours of work in a week. What is the percent increase in his salary for an hour?
Pick one:  A) 11 1/3  B) 12 1/4  C) 13 1/5  D) 14 2/7  E) 15
280 is multiple of both 40 and 35   so I would rather take this value as the salary.   40 hrs 280$   1 hr=7$   Similarly   35 hrs 280$   1 hr=8$   Now   8-7= 
<gadget id="calculator">  8-7</gadget>
<output>1</output>
1$ increase in salary per hour now to calculate %   1/7*100=14 2/7   ANSWER:14 2/7
<result>D</result>
Before a salary hike, the weekly salary of a worker for 40 hours in a week was as much as he is paid now for 35 hours of work in a week. What is the percent increase in his salary for an hour?