Question

Lin runs 6 laps around a track in 9 minutes ( use ratio table)A. How many minutes per lap is that?B. How many laps per minute is that?C. If Lin runs 21 laps at the same rate, how long does it take her?

Answer 1

Given

Lin runs 6 laps around a track in 9 minutes

Part A

How many minutes per lap is that?



`\begin{gathered} 6\text{laps =9minutes} \\ 1\text{ lap =}(9)/(6)\text{minutes} \\ 1\text{lap}=(3)/(2)\text{minutes} \\ 1lap=1\min utes\text{ 30seconds} \end{gathered}`

The final answer

1.5minutes per lap

Part B

How many laps per minute is that?

`\begin{gathered} 6\text{laps =9minutes} \\ (6)/(9)\text{laps =1minute} \\ (2)/(3)\text{laps}=1\text{minute} \\ 0.66666666667lap=1\min ute \end{gathered}`

The final answer

0.66666666667lap per minute

Part c

If Lin runs 21 laps at the same rate, how long does it take her?

`\begin{gathered} 6\text{laps =9minutes} \\ 21\text{laps =y minutes} \\ (6)/(21)=(9)/(y|) \\ \text{cross multiply} \\ 6y=189 \\ \text{divide both sides by 6} \\ (6y)/(6)=(189)/(6) \\ y=31.5\text{ minutes} \end{gathered}`

The final answer

Lin runs 21 laps for 31.5 minutes