Answer:
Options D and F are possible
Explanation:
Let w represent walking
Let b represent basketball
The given inequalities are
4w + 5b ≥ 400 ........(1)
4w + 5b ≤ 600 .........(2)
Substitute each options in the inequalities to get the possible solution
For the first option,
w = 40 minutes walking
b = 40 minutes basketball
So we have
4(40) + 5(40) ≥ 400
160 + 200 ≥ 400
360 ≥ 400
4(40) + 5(40) ≤ 600
360 ≤ 600
Option A is not possible
For option B
w = 60 minutes walking
b = 20 minutes basketball
So we have
4(60) + 5(20) ≥ 400
240 + 100 ≥ 400
340 ≥ 400
4(60) + 5(20) ≤ 600
340 ≤ 600
This is also not possible
For option C
w = 20 minutes walking
b = 60 minutes basketball
So we have
4(20) + 5(60) ≥ 400
80 + 300 ≥ 400
380 ≥ 400
4(20) + 5(60) ≤ 600
380 ≤ 600
Option C is not possible
For option D
w = 50 minutes walking
b = 50 minutes basketball
So we have
4(50) + 5(50) ≥ 400
200 + 250 ≥ 400
450 ≥ 400
4(50) + 5(50) ≤ 600
450 ≤ 600
Option D is possible
For option E
w = 60 minutes walking
b = 80 minutes basketball
So we have
4(60) + 5(80) ≥ 400
240 + 400 ≥ 400
640 ≥ 400
4(60) + 5(80) ≤ 600
640 ≤ 600
Option E is not possible
For option F
w = 70 minutes walking
b = 60 minutes basketball
So we have
4(70) + 5(60) ≥ 400
280 + 300 ≥ 400
580 ≥ 400
4(70) + 5(60) ≤ 600
580 ≤ 600
Option F is also possible
Therefore options D and F are the possible solutions for the number of minutes Joshua can use in taking part in each activity