Question

A motorist takes 4,5 hours to reach his destination at 80 km/h. If he wants to complete his journey in 4 hours, at what speed must he travel? If he drives at 110 km/h, how long will the journey be? Give answer in hours and minutes.​

Answer 1

At 80 km/h you’d travel 80 km in one hour.

After two hours at 80 km/h, you would travel 2 h * 80 km/h = 160 km.

After three hours at 80 km/h, you’d travel 3 * 80 = 160 km.

After N hours at 80 km/h, N * 80 km.

So, after 5 hours, the answer is: 5 * 80 = 400.

Explanation: