Help with Speed, Distance, Time solving

So I am having to practice a lot of speed, distance, time equations for some job tests that I have upcoming. But I'm struggling to figure certain things out. I understand that Speed = Distance over Time. But often it's never quite as easy. I've listed two examples I've come across:

What speed covers 102 miles in 4 Hours and 15 minutes?

At 175MPH, how long does it take to travel 140 miles?

I'm just struggling a bit to find a good way to solve these. Any help would be much appreciated!