Question

a mam cycles to his office from his house at a speed of 5 km/hour and reaches 10 minutes late . if hi cycles at a spaad of 6 km/hour ,he reaches 10 minutes early. what is the distance between the office and the house

Answer 1

Hi Mani,

Let d be the distance
let t be the time taken (without being early or late)

the hint here is that the distance remains same in both cases
so the distances in given two cases can be equated to each other

speed = distance / time
distance = speed * time

5*(t+10/60) = 6*(t-10/60)
=> 5t + 50/60 = 6t - 1
=> t = 50/60 + 1
=> t = 110/60
=> t = 11/6 hrs

note: 10 minutes = 10/60 hrs

so distance
= 6*(t-10/60)
= 6t - 1
= 6*(11/6) - 1
= 11-1
= 10 km

So the distance of the office from house is 10 km

Hope it helped.
Let me know if any doubts.
Cheers !!!