Walking 7/6 of his usual rate, a boy reaches his school 4 min early. Find his usual time to reach the school?	Choose the correct choice from the following answers:
A) 11
B) 15
C) 16
D) 28 min
E) 19
Speed Ratio = 1:7/6 = 6:7   Time Ratio = 7:6   1 -------- 7   4 --------- ? è 28 m   Answer: 28 min
<result>D</result>
Walking 7/6 of his usual rate, a boy reaches his school 4 min early. Find his usual time to reach the school?