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.
To find how far Brian ran in 18 minutes, divide the distance he ran in 40 minutes by the time ratio: 5 kilometers / 40 minutes = 1 kilometer / 8 minutes
Then multiply the ratio by the number of minutes Brian ran: 1 kilometer/8 minutes * 18 minutes = 2.25 kilometers. Answer: \boxed{2.25}.
To find out how far Brian ran in 18 minutes, we can set up a proportion using the ratio of time to distance.
The proportion can be set up as follows:
5 kilometers / 40 minutes = x kilometers / 18 minutes
To solve for x, we can cross-multiply:
40 minutes * x kilometers = 18 minutes * 5 kilometers
Now divide both sides by 40 minutes:
x kilometers = (18 minutes * 5 kilometers) / 40 minutes
x kilometers = 90 kilometers / 40 minutes
Simplifying further:
x kilometers = 9/4 kilometers
Therefore, Brian ran 9/4 kilometers in 18 minutes. Since 9/4 is already a decimal, the answer is 9/4 or 2.25 kilometers.
To find out how far Brian ran in 18 minutes, we can use proportions since Brian's running rate remains constant.
First, we need to determine Brian's running rate in kilometers per minute by dividing the total distance he ran by the total time it took him to run that distance:
Running rate = Distance / Time
Running rate = 5 kilometers / 40 minutes
Running rate = 0.125 kilometers per minute
Now, we can set up a proportion to find out how far Brian ran in 18 minutes:
Distance in 18 minutes / Time = Running rate
Distance in 18 minutes / 18 minutes = 0.125 kilometers per minute
Distance in 18 minutes = 18 minutes * 0.125 kilometers per minute
Distance in 18 minutes = 2.25 kilometers
Therefore, Brian ran 2.25 kilometers in 18 minutes.