Ok, so if you are going 45mph, then you are basically going to go 45 miles in one hour. The rate is x miles per hour. The time would be distance per x.
Therefore, 45mph represents the rate, and 3 hours represents the time.
When you take the formula r x t; in this case, it woul be 45 times 3, because you would be traveling for 3 hours, and each hour you would have traveled 45miles.
The answer you are looking for is that the family would have traveled 135 miles in 3 hours.
