04:57 <@Inc> Your aunt and uncle have been visiting at your home. Five minutes after they drive away you realize that they forgot their luggage. You happen to know they drive
slowly, so you get in your car and drive to catch up with them. Your average speed is 10 miles an hour faster than their average speed, and you catch up with them
in 25 minutes. How fast did you drive
04:57 <@Inc> use the following model
04:57 <@Inc> your speed = their speed + 10 mph
04:58 <@Inc> your speed*your time in hours = their speed*their time in hours
04:58 <@Inc> so x=y+20
04:58 <@Inc> x= your speed
04:58 <@Inc> y = their speed
04:58 <@Inc> x*5/12=y*1/2