Ray and Jane live 150 miles apart. Each drivers toward the other's house along a straight road connecting the two, Ray at a constant rate of 30 miles per hour and Jane at a constant rate of 50 miles per hour. If Ray and Jane leave their house at the same time, how many miles from are they from Ray's house when they meet?

I already know the answer, since the teacher told us, but she didn't tell us how to solve it. The answer is 56.25 miles. I just need to know how to get the answer.