Question

Really need help..I can't figure out how?

A van travelling at 60km/h left Town A for Town B at 7.00am. At 7.30am, a car left Town A for Town B. If the car travelled at an average speed of 80km/h, at what time would it catch up with the van?

Answer 1

When the car catches up with the van, they would have both traveled the same distance

let the time from 7:30 am to the catch-up time be t hrs.
distance covered by car = 80t
distance covered by van = 60t + (1/2)(60)
= 60t + 30

80t = 60t + 30
20t = 30
t = 3/2
3/2 hours added to 7:30 am would make it 9:00 am



check:
the car went 80t
= 1.5 hrs at 80 km/h or 120 km

the van went 60t + 30
= (3/2)(60) + 30
= 120