Answer:
The possible solutions are:
50 minutes walking, 50 minutes basketball
70 minutes walking, 60 minutes basketball
Explanation:
These following inequalities need to be respected:
4w + 5b ≥ 400
4w + 5b ≤ 600
40 minutes walking, 40 minutes basketball
This means that w = 40, b = 40. So
4w + 5b = 4*40 + 5*40 = 360
This is lower than 400, so it is not a possible solution.
60 minutes walking, 20 minutes basketball
This means that w = 60, b = 20. So
4w + 5b = 4*60 + 5*20 = 340
This is lower than 400, so it is not a possible solution.
20 minutes walking, 60 minutes basketball
This means that w = 20, b = 60. So
4w + 5b = 4*20 + 5*60 = 380
This is lower than 400, so it is not a possible solution.
50 minutes walking, 50 minutes basketball
This means that w = 50, b = 50. So
4w + 5b = 4*50 + 5*50 = 450
This is between 400 and 600 calories, so it applies.
60 minutes walking, 80 minutes basketball
This means that w = 60, b = 80. So
4w + 5b = 4*60 + 5*80 = 640
This is higher than 600, so it is not a possible solution.
70 minutes walking, 60 minutes basketball
This means that w = 70, b = 60. So
4w + 5b = 4*70 + 5*60 = 580
This is between 400 and 600 calories, so it applies.