Start by writing a rate that compares the number of miles to hours.
D
Practice makes perfect
We are asked to find how many miles per hour Debra can run. We know that she can run 20 12 miles in 2 14 hours. Let's start by writing a rate that compares the number of miles to hours.
20 12 miles/2 14 hours
We can find the how fast Debra can run by calculating the unit rate. We can do this by simplifying the expression that we got. Let's ignore the units for now.
20 12/2 14Notice that we have a complex fraction that we want to simplify. We will start by writing it as a division problem.
20 12/2 14 = 20 12 Ă· 2 14
Next, we will write the mixed numbers as improper fractions. Let's start with 20 12.
We found that 2 14 is equal to 94. Now we can replace the mixed numbers with improper fractions.
20 12 Ă· 2 14 = 41/2 Ă· 9/4
Next, we will write the division by 94 as multiplication by the reciprocal of 94, which is 49.
41/2 Ă· 9/4 = 41/2 * 4/9
Finally, we can evaluate the expression.
