Final answer:
Deandre's amount of exercise per day is represented by the variable t, where t is greater than or equal to 40 minutes. This shows that Deandre exercises for at least 40 minutes each day, and aligns with advice that encourages starting with shorter exercise sessions and gradually increasing them.
Step-by-step explanation:
To represent Deandre's amount of exercise (in minutes per day) using a variable, let's use t to denote the time he exercises daily. Since Deandre exercises no less than 40 minutes per day, we write this mathematically as t ≥ 40. This means that t can be any number that is 40 or more.
If we consider additional information provided, we see that students may have different exercise habits. For example, it is noted that 75 percent of the students exercise for 60 minutes or less daily, and about half of the students fall within the 20 to 60-minute exercise window.
Further, information on a broad range of possible exercise durations is provided, from low intensity or skill-based activities, a moderate exercise program, to an intensive endurance program. Overall, it's important to note that starting with smaller amounts of exercise and then gradually increasing the intensity and duration can be beneficial, as even modest amounts of physical activity can contribute to overall health.