For her exercise today, Keiko plans to both run and swim. Let r be the number of laps she runs and let s be the number of laps s
he swims. Each lap she runs takes her 5 minutes, and each lap she swims takes her 3 minutes. She wants to exercise for at least 30 minutes today. Using the values and variables given, write an inequality describing this.
We know Keiko wants to do exercise at least 30 minutes a day, and she wants ideally to mix up the activities, by combining running and swimming into her schedule.
Since each lap she runs takes 5 minutes and each lap she swims takes 3 minutes, these will be the left side of the inequality:
5r + 3s
She wants to exercise at least 30 minutes a day, so...
5r + 3s ≥ 30
she could do 3 laps of running and 5 laps of swimming for example.
