Question

A total of 180 students attended a concert. Of these, 60 students were under 18 years old, 40 were between 18 and 25 years old, and the remaining students were over 25 years old. How many students were over 25 years old?

• A. 60
• B. 80
• C. 100
• D. 120

Hint:

In problems with multiple categories that make up a whole, the fundamental logic is often: \textbf{Part1 + Part2 + ... + PartN = Total}. You can rearrange this to find any missing part.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
This is a word problem that can be solved using simple arithmetic. We need to find the size of a remaining group after subtracting the sizes of the known groups from the total.
Step 2: Detailed Explanation:
The given information is:
- Total number of students = 180
- Number of students under 18 = 60
- Number of students between 18 and 25 = 40
First, find the total number of students in the two known age groups:
\[ \text{Total in known groups} = 60 + 40 = 100 \text{ students} \] The remaining students are in the "over 25" group. To find this number, subtract the total of the known groups from the overall total:
\[ \text{Students over 25} = (\text{Total students}) - (\text{Total in known groups}) \] \[ \text{Students over 25} = 180 - 100 = 80 \text{ students} \] Step 3: Final Answer:
There were 80 students over 25 years old. This corresponds to option (B).