Walking 5/4 of his usual rate, a boy reaches his school 4 min early. Find his usual time to reach the school?
Choose the most appropriate option: A) 22 B) 99 C) 27 D) 28 E) 20
Speed Ratio = 1:5/4 = 4:5   Time Ratio = 5:4   1 -------- 5   4 --------- ?20 m.Answer:20
<result>E</result>
Walking 5/4 of his usual rate, a boy reaches his school 4 min early. Find his usual time to reach the school?