Mrs. M drove 10 minutes at 60 miles per hour, then 20 minutes at 30 miles per hour. For the rest of the hour, she drove at a rate that put her 48 miles from her starting point. What was the rate?
To calculate the distance Mrs. M traveled during the first 10 minutes, we use the formula: distance = rate x time
Distance = 60 miles per hour x 10 minutes = 10 miles
Next, we calculate the distance Mrs. M traveled during the next 20 minutes:
Distance = 30 miles per hour x 20 minutes = 10 miles
Therefore, in the first 30 minutes Mrs. M traveled a total of 20 miles.
To find out how far Mrs. M was from her starting point after the first 30 minutes, we subtract the total distance traveled from the 48 miles:
48 miles - 20 miles = 28 miles
So, Mrs. M was 28 miles from her starting point after the first 30 minutes.
Now we calculate how far she traveled in the remaining time:
Remaining time = 60 minutes - 30 minutes = 30 minutes
Let's say she traveled at a rate of x miles per hour during this time. With this rate she traveled x miles in 30 minutes.
Therefore, the total distance she traveled was 20 miles + x miles = 48 miles
20 miles + x miles = 48 miles
x = 48 miles - 20 miles
x = 28 miles
So, Mrs. M drove the rest of the hour at a rate of 28 miles per hour.