When darcy's school bus travels at 30 miles per hour, it gets from her home to school in 12 minutes. what is the speed of darcy's bus if it makes the same trip in 18 minutes?

We know that
speed=distance/time> distance=speed*time

step 1
find the distance with
speed=30 miles/hour> 30 miles/60 minutes> 0.5 miles/minute
time=12 minutes
distance=speed*time> distance=0.5/12> distance=6 miles

the distance from home to school is 6 miles

step 2
find the speed with
distance=6 miles
time=18 minutes
speed=6/18> 0.33 miles/minute> *60> 20 miles/hour

the answer is
20 miles/hour  or 0.33 miles/minutes