7-64. Write and solve an equation for the situation below. Define any variables and write your solution as a sentence. Jennifer has a total of four and one half hours to spend on the beach swimming and playing volleyball. The time she spends playing volleyball will be twice the amount of time she spends swimming. How long will she do each activity?

Let \( s \) represent the time in hours Jennifer spends swimming. Since she spends twice that time playing volleyball, we can express the time spent on volleyball as \( 2s \). The total time spent on both activities is given by the equation: \[ s + 2s = 4.5 \] This simplifies to: \[ 3s = 4.5 \] Now, dividing both sides by 3 gives: \[ s = 1.5 \] So, Jennifer spends 1.5 hours swimming and \( 2 \times 1.5 = 3 \) hours playing volleyball. In summary, Jennifer will swim for 1.5 hours and play volleyball for 3 hours.