To find out how fast is she walking in mph, we just need to know how long distance she beats in one hour. There are many ways to do it.
We know that 3/4 of an hour is 3/4 of an hour, so 2 1/2 is also 3/4 of what she can beat, so we need to find out how many is remaining 1/4 of 2 1/2 miles and then just add it.
1/4 * 2 1/2 =
= 1/4 * 5/2 =
= 5/8
2 1/2 + 5/8 =
= 5/2 + 5/8 =
= 20/8 + 5/8 =
= 28/8 =
= 3 4/8 =
= 3 1/2
Answer: Melitta walks 3.5 miles per hour.
