Salary Percent GMAT, GRE Problem

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?

A. 11 1/3
B. 12 1/4
C. 13 1/5
D. 14 2/7
E. 15





x = 560 for 3hrs
1 hr = 16
640 for 40hrs

changeoriginal=percent100$\frac{change}{original}=\frac{percent}{100}$
80560x100=1007$\frac{80}{560}x100=\frac{100}{7}$


D