Olive walks at a rate of 4 miles per hour. She lives 2 miles from the news station. How long would it take her to walk home from the news station?

In 30 minutes she will get to the train staion

4/1 = 2/x ... 4 miles to 1 hr = 2 miles to x hrs

cross multiply because this is a proportion

(4) (x) = (1) (2)

4x = 2

x = 2/4 reduces to 1/2 ... so she can walk 2 miles in 1/2 hr (or 30 minutes)