There camp is 325 miles away they will be there at the afternoon for a 3 hour drive
If they are driving at 50 miles per hour and want to get there at 3 hours
50m x 3h = 150
Which is not there mark they are 175 miles away
175 / 50 is 3.5
If it took them 3 hours just to get up to 150,
It took them 3.5 hours to get to 175
If you add 150 + 175 = 325
325 was them goal mileage.
175 miles = 3.5 hours
150 miles = 3 hours
3.5 + 3 is 6.5
To check it we do 6.5 x 50
6.5 x 50 = 325
The number of hours is 6.5
