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 choices:
A) 22
B) 99
C) 27
D) 28
E) 20
Speed Ratio = 1:7/6 = 6:7   Time Ratio = 7:6   1 -------- 7   4 --------- ? è 28 m.Answer:28
<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?