By walking at 4/5 of his usual speed, Mohan is 6 minute late to his office. find his usual time to cover the distance.	Choices
A) 25 minutes B) 23 minutes C) 24 minute D) 26 minute E) None of these
Here, Change in time = 6 and a/b = 4/5   We have, change in time = (b/a - 1) x original time   =&gt; Original time = Change in time/(b/a - 1)   =&gt;6(5/4 - 1) = 24 minute.   ANSWER:24 minute
<result>C</result>
By walking at 4/5 of his usual speed, Mohan is 6 minute late to his office. find his usual time to cover the distance.