If a man walks to his office at 5/4 of his usual rate, he reaches office 30 minutes early than usual. What is his usual time to reach office. Choose the correct choice from the following answers:
A) 2 hrs
B) 2 1⁄2 hrs
C) 1 hr 50 min
D) 2 hrs 15 min
E) None of these
usual time × (4⁄5 - 1) = -30⁄60   ⇒ usual time = 1⁄2 × 5 = 21⁄2 hrs   Answer 2 1⁄2 hrs
<result>B</result>
If a man walks to his office at 5/4 of his usual rate, he reaches office 30 minutes early than usual. What is his usual time to reach office.