This question is all about distance speed and time. I’m sure you will have learnt about it at school but here’s a quick refresher in case you’ve forgotten.

So, the first thing you need to do is draw a triangle like this one and you need to populate the letters in alphabetical order so D at the top, S to the left and T to the right. In this example we’ve got a train that travels 1,250 kilometers in three hours and we need to work out what the average speed is by referring to the triangle.

If you cover over the S which is what you want to work out, you can see that you have D over T. Populate this with the values that you have so 1,250 divided by 3 which is 417 km/h.

Now this triangle will work if you’re trying to find out the distance so distance would be speed multiplied by time or if you’re trying to work out the time then that’s distance divided by speed.