By walking at 3/4th of his usual speed, a man reaches office 20 minutes later than usual. What is his usual time?
Choose the correct option
A) 40min	B) 50min	C) 65min	D) 60min	E) 70min
let T be the usual time.   time spent=4T/3   therefore, 4T/3=T+20   4T=3T+60...therefor T=60min   ANSWER:60min
<result>D</result>
By walking at 3/4th of his usual speed, a man reaches office 20 minutes later than usual. What is his usual time?