Here's a problem that I can't seem to solve. It was discussed to us last week, but I had a fever so I wasn't able to understand the answer and solution.
Due to inclement weather, the pilot of a plane slows down the plane’s regular flying rate by $25. This results to an additional $1.5$ hours in covering the 3,000-km distance to its regular time required for the trip. Find the regular rate of the trip.