Answer:
15 multiple choice questions
5 free response questions
Step-by-step explanation:
This is basically a systems of equations word problem.
To solve this, we need to create two equations that represent this scenario. Let's suppose [tex]m[/tex] represents the amount of multiple choice questions and [tex]f[/tex] represents the amount of free-choice questions.
We can create the following equations:
[tex]4m + 8f = 100[/tex]
[tex]m+f=20[/tex]
To solve for m and f, we can use elimination.
Let's multiply the equation [tex]m+f=20[/tex] by -4.
[tex]-4m - 4f = -80[/tex]
Great! Now let's add this equation to our first one, [tex]4m + 8f = 100[/tex].
[tex]4m + 8f = 100[/tex]
[tex]-4m - 4f = -80[/tex]
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[tex]0m + 4f = 20[/tex]
[tex]4f=20[/tex]
Dividing both sides by 4 get us [tex]f=5[/tex].
So there are 5 free choice questions. To find m, we can substitute inside the equation [tex]m+f=20[/tex]
[tex]m+5=20\\\\m=20-5\\\\m=15[/tex]
So there are 15 multiple choice questions.
Hope this helped!
