Question

for his exercise today, chau plans to both run and swim. let ( r ) be the number of laps he runs and let ( s ) be the number of laps he swims. each lap he runs takes him 4 minutes, and each lap he swims takes him 2 minutes. he wants to exercise for at least 30 minutes today. using the values and variables given, write an inequality describing this.

Explanation:

Step1: Calculate running time

Each run lap takes 4 minutes, so total running time is $4r$ minutes.

Step2: Calculate swimming time

Each swim lap takes 2 minutes, so total swimming time is $2s$ minutes.

Step3: Set up total time inequality

Total exercise time is at least 30 minutes, so sum the two times and set it greater than or equal to 30.
$4r + 2s \geq 30$

Answer:

$4r + 2s \geq 30$