Question

A car and a scooter are moving in opposite directions and cross each other at a common point. if the average speed of the car is 50 miles per hour and that of the scooter is 40 miles per hour,after how many hours will they be 180 miles apart?

Answer 1

As they are traveling in opposite directions you need to do 50 + 40 to find out how far apart they travel every hour. 50 + 40 = 90. So you know that they are 90 miles apart every hour.
180 / 90 = 2. so you know that it takes them 2 hours to be 180 miles apart.