Answer:
1 1/2 miles or 3/2 miles
Explanation:
We can represent the person's walking rate as the ratio 1/2 mile : 20 minutes. Since we can multiply both sides of a ratio without changing the rate, we can rewrite it as ---> 3*(1/2) miles : 3*20 minutes = 3/2 miles : 60 minutes =
1 1/2 miles : 1 hour
An alternative way would be to convert 20 minutes into 1/3 of an hour. We can set up an equation:
mph * 1/3 hour = 1/2 mile
Therefore, the mph must be 1/2 divided by 1/3, because we are multiplying by 1/3, and division is the opposite of multiplication.
mph = (1/2)/(1/3) = (1/2) * 3 = 3/2 or 1 1/2