Question

A person goes from his residence to office at speed of 3 kms per hour, reaches late by 8 mutes and if he increases his speed 4 km per hour, he reaches his office ...

Answer 1

Can u plz refer this solution pf another question as same to solve this question :

(Let us say that the actual distance between Ram's house and school is 'd' km and the ideal time to cover the distance is 't' hours.

When he walks at 5 kmph, he reaches 5 minutes (or 1/12 hours) early
=> d/5 = t - 1/12
=> t = d/5 + 1/12

When he walks at 4 kmph, he reaches 5 minutes (or 1/12 hours) late
=> d/4 = t + 1/12
=> t = d/4 - 1/12

Using the above equations, we can say 
d/5 + 1/12 = d/4 - 1/12
=> d/4 - d/5 = 1/12 + 1/12
=> d/20 = 1/6
=> d = 20/6 = 3.33 km)