Have world problem and I don't get it please explain step by step simplify and show me as many ways as possible cause one might be easier than other !!

Question

A bicycle travels at constant speed of 15km/hr. Bus starts 195km behind bicycle and catches up to bicycle in 3 hrs. What's average speed of bus in km/hr????

Answer 1

They both travel for time t = 3 hours
the bike goes:
d = 15 t

the bus goes
d + 195 = v t
so
d = v t - 195

but t = 3 so

15(3) = v(3) - 195

45 = 3 v - 195
3 v = 240
v = 80 km/h

Answer 2

or, you can look at it like this. The bus makes up 195km in 3 hours, so it is going 195/3 = 65 km/hr faster than the bike.

15+65 = 80 km/hr