Question

A test is worth a total of 150 points and contains 70 questions. Some of the questions are worth 2 points and some are worth

Answer 1

Answer:

65 two-point questions, and 5 four-point questions.

Emma answered 2 four-point questions.

Step-by-step explanation:

1. Assigning variables and writing equations

We will set the number of 2 point questions as "x" and number of 4 point questions as "y"

We know that:

x+y=70 (number of 2 point questions+number of 4 point questions=total number of questions)

2x+4y=150 (number of points that a two point question is worth*number of two point questions+number of points that a four point question is worth*number of four point questions=total points on test)

2. Combining equations

x+y=70, 2x+4y=150

We will solve one of these equations.

x+y=70

x=70-y

Next, we will substitute the other equation with this solution.

2*(70-y)+4y=150

140-2y+4y=150

2y=10

y=5

Use this solution to find x.

x+y=70

x+5=70

x=65

We found that there are 65 two-point questions, and 5 four-point questions.

3. Finding Emma's test results

In this case, we know how many two-point questions she answered. So, we will only be using one variable in this equation, which is y.

46*2+4y=100

92+4y=100

4y=8

y=2

So, she answered 2 questions correctly.