In order to solve this problem, we need to use proportions. Notice that we need to find her unit rate, i.e., the distance she runs in one minute.
We have:
time distance
1/3 min 150 feet
1 min x
Now, we cross multiply those values to obtain:
(1/3 min)x = (1 min)(150 feet)
Now, we can divide both sides of the above equation by (1/3 min) to find the value of x:
(1/3 min)x/(1/3 min) = (1 min)(150 feet)/(1/3 min)
x = (150 feet) (1 min) * (3/min) dividing by a fraction is the same as multiplying by its inverse
x = 150 * 3 feet (min/min)
x = 450 feet
Thus, she runs 450 feet in one minute. That means her unit rate is 450 feet per minute.