?A woman works out by running and swimming. When she runs, she burns 7 calories per minute. When she swims, she burns 8 calories per minute. She wants to burn at least 336 calories in her workout. Write an inequality that describes the situation.

Let x represent the number of minutes running and y the number of minutes swimming. Because x and y must be positive, limit the boarders to quadrant I only.

1 Answer
May 2, 2018




#x# be the number of minutes she runs, and

#y# be the number of minutes she swims.

Because she burns 7 calories/minute while running and 8 calories/minute while swimming the expression for the total number of calories she burns is


We want this quantity to be at least 336, so our inequality is


Solving this for #y# we have


The advantage of putting the inequality in this form is that it makes it easier to plot. See the plot below.

Original Drawing