How do i solve this problem? what do i do next?

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.

How to use order of operation in 20 divide by 4 multiply 5 = 1

15m is what percent of 60m; 3m; 30m; 1.5 km? the last one is km not m