Final answer:
The constant of proportionality in Johnny's training is 5, meaning that he runs 5 minutes for every minute he walks. Calculating how long he can run for 35 minutes of walking, Johnny can run for 175 minutes.
Step-by-step explanation:
The constant of proportionality is the fixed number that relates two variables that are directly proportional to each other. In the case of Johnny's training program, where he runs for 5 minutes and then walks for 1 minute, we can determine the constant of proportionality by the ratio of running time to walking time, which is 5/1. This gives us the constant of proportionality, which is option A: 5. This means that for every 1 minute Johnny walks, he runs for 5 minutes.
To calculate how long Johnny can run if he walks for 35 minutes, we can use the constant of proportionality and set up a proportion:
- Walk : Run = 1 : 5
- 35 : x = 1 : 5
By cross-multiplying to solve for x, we get:
Therefore, if Johnny walks for 35 minutes, he can run for 175 minutes.