College

Tiffany is taking a 42-question test worth 100 points. The test includes two-point and four-point questions. How many of each type of question are on the test?

Which equations represent the scenario, where [tex]t[/tex] represents the number of two-point questions and [tex]f[/tex] represents the number of four-point questions? Check all that apply.

A. [tex]t + f = 42[/tex]
B. [tex]t + f = 100[/tex]
C. [tex]2t + 4f = 42[/tex]
D. [tex]2t + 4f = 100[/tex]
E. [tex]4t + 2f = 100[/tex]

Answer :

Certainly! Let's break down the problem to find out how many two-point and four-point questions are on Tiffany's test.

1. Understanding the Problem:
- The test has a total of 42 questions.
- The entire test is worth 100 points.
- There are two types of questions: two-point questions and four-point questions.
- We need to find out how many of each type of question is on the test.

2. Define the Variables:
- Let [tex]\( t \)[/tex] be the number of two-point questions.
- Let [tex]\( f \)[/tex] be the number of four-point questions.

3. Set Up the Equations:
- Since the total number of questions is 42, we can write the equation:
[tex]\[
t + f = 42
\][/tex]
- Since the total points are 100, and each two-point question contributes 2 points and each four-point question contributes 4 points, we set up the equation:
[tex]\[
2t + 4f = 100
\][/tex]

4. Check the Equations:
- The equation [tex]\( t + f = 42 \)[/tex] represents the total number of questions.
- The equation [tex]\( 2t + 4f = 100 \)[/tex] represents the total number of points.

5. Identifying Correct Equations:
- Both [tex]\( t + f = 42 \)[/tex] and [tex]\( 2t + 4f = 100 \)[/tex] are correct representations of the problem.

Let's proceed with these equations to solve for [tex]\( t \)[/tex] and [tex]\( f \)[/tex].

6. Solving the Equations:
- From the first equation, express [tex]\( t \)[/tex] in terms of [tex]\( f \)[/tex]:
[tex]\[
t = 42 - f
\][/tex]
- Substitute [tex]\( t = 42 - f \)[/tex] into the second equation:
[tex]\[
2(42 - f) + 4f = 100
\][/tex]
- Simplify and solve for [tex]\( f \)[/tex]:
[tex]\[
84 - 2f + 4f = 100
\][/tex]
[tex]\[
2f = 16
\][/tex]
[tex]\[
f = 8
\][/tex]

7. Find the Value of [tex]\( t \)[/tex]:
- Substitute [tex]\( f = 8 \)[/tex] back into the equation [tex]\( t = 42 - f \)[/tex]:
[tex]\[
t = 42 - 8
\][/tex]
[tex]\[
t = 34
\][/tex]

Therefore, there are 34 two-point questions and 8 four-point questions on the test.