By walking at 3/4 of his usual speed, a man reaches his office 20 minute later than usual. this usual time is?
Correct Answer: 60 minute
Explanation:
At a speed of 3/4 of the usual speed, the time taken is 4/3 of the usual time
= (4/3 of usual time ) – (usual time ) = 20min.
⇒ 4x/3 -x = 20
⇒ x/3 =20
⇒ x=60 min
