Answer:
<u>There are 10 multiple-choice questions and 15 short-answer questions in the test</u>
Step-by-step explanation:
1. Let's review the information given to us to answer the question correctly:
Test worth 80 points
Multiple-choice questions are worth 2 points
Short-answer questions are worth 4 points
Multiple-choice questions + Short-answer questions = 25
2. How many multiple-choice questions are there?
Let's solve this problem, this way:
m = Multiple-choice questions
s = Short-answer questions
Our equations system is:
m + s = 25
2m + 4s = 80
Solving for m in the 1st equation:
m + s = 25
m = 25 - s
Substituting m in the 2nd equation and solving for s:
2m + 4s = 80
2 * ( 25 - s) + 4s = 80
50 - 2s + 4s = 80
2s = 80 - 50
2s = 30
<u>s = 30/2 = 15</u>
Substituting s in the 1st equation and solving for m:
m = 25 - 15
<u>m = 10 </u>
<u>There are 10 multiple-choice questions and 15 short-answer questions in the test</u>
Number of students that have rabbits = 43
Number of students that have birds = 40
43 - 40 = 3
Thus, 3 more students have rabbits that birds.
Hence, the answer is A.
