Brian ran a 5-kilometer race in 40 minutes. How far did he run in 18 minutes? Write your answer as a decimal and do not round.(1 point)
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To find out how far Brian ran in 18 minutes, we can set up a proportion based on the ratio of time and distance. Since we know that Brian ran 5 kilometers in 40 minutes, we can write the proportion as:
\[ \frac{5\, \text{km}}{40\, \text{min}} = \frac{x\, \text{km}}{18\, \text{min}} \]
Where x is the distance Brian ran in 18 minutes. Now we can solve for x by cross-multiplying:
\[ 40x = 5 \times 18 \]
\[ 40x = 90 \]
\[ x = \frac{90}{40} \]
Simplifying the fraction gives us:
\[ x = 2.25 \]
Thus, Brian ran 2.25 kilometers in 18 minutes.
\text{Distance} = \text{Rate} \times \text{Time}
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The distance Brian ran is given as 5 kilometers and the time he ran is 40 minutes. We can use this information to calculate his rate:
$$
5\text{ kilometers} = \text{Rate} \times 40\text{ minutes}
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Dividing both sides by 40 minutes:
$$
\frac{5\text{ kilometers}}{40\text{ minutes}} = \text{Rate}
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Simplifying the fraction:
$$
\frac{1}{8}\text{ kilometer per minute} = \text{Rate}
$$
Now we can use his rate to find how far he ran in 18 minutes:
$$
\text{Distance} = \text{Rate} \times \text{Time} = \left(\frac{1}{8}\text{ kilometer per minute}\right) \times 18\text{ minutes}
$$
Multiplying the rate and time together:
$$
\text{Distance} = \frac{1}{8} \times 18\text{ kilometers}
$$
Simplifying the expression:
$$
\text{Distance} = \frac{18}{8}\text{ kilometers} = \boxed{2.25}\text{ kilometers}
$$
To determine how far Brian ran in 18 minutes, we can use the concept of proportionality.
We know that Brian ran 5 kilometers in 40 minutes.
To find the distance he ran in 18 minutes, we can set up a proportion:
\(\frac{5 \text{ kilometers}}{40 \text{ minutes}} = \frac{x \text{ kilometers}}{18 \text{ minutes}}\),
where \(x\) represents the distance Brian ran in 18 minutes.
To solve for \(x\), we can cross multiply and then divide:
\(40x = 5 \times 18\)
\(40x = 90\)
\(x = \frac{90}{40}\)
\(x = 2.25\)
Therefore, Brian ran 2.25 kilometers in 18 minutes.