He notices that at 1045 am they are passing a marker labeled

He notices that at 10:45 a.m. they are passing a marker labeled 101, and at 11:00 a.m. the car reaches marker 119. what is the speed?

Solution

He notices that at 10:45 a.m. they are passing a marker labeled 101, and at 11:00 a.m. the car reaches marker 119. what is the speed?
since i had to figure out how this other guy got 18x4=72...i figure id explain why so people can actually understand how to solve this.
MILE markers from 101 to 119 means 18 miles in distance
Took them 15mins because 11:00am-10:45am=15mins
15 mins is 1/4th of 1hour
so 15(4)=1hr
so 18(4)=72miles
18miles/15mins => (18mi(4))/(15min(4))=>72mi/60mins=> 72mi/hr=> 72mph