Hi all, I was wondering whether someone can enlighten me in the case of working out this easy question that has stumped me. I came across a question whereby I was required to work out the speed.

Question: A person in a car travel 10km in the space of 30minutes, what was their average speed?

I know how I would work this out using Speed = Distance / Time. However, on this occassion because I am doing a smaller number divided into a larger number it comes out as 0.333333 which is wrong. I know the answer it 20kmh but I don't know how to perform the working out. If someone can help me with this I would greatly appreciate it