Question

A high school teacher teaches three classes per day. Her first class has double the number of students as her

second class, while her third class has 5 more students than her second class. In total, she teaches 65 students.
The equation 2x + x + (x + 5) = 65 represents this scenario, where x is the number of students in her
second class.
How many students are in her second class?

Answer 1

Answer: 15 students in her second class.

Explanation:

Let A, B, and C stand for the number of students in each class. See the attached table.

The column labelled "Students" is formed by assinging B to the second class and finding how the other two classes relate to B. Class A has twice as many students as class B, so A = 2B. Class C has 5 more students than B, so C = B+5.

The total students amount to 65, whcih is the sum of A, B, and C:

A + B + C = 65

Substitute the values of A and C into this equation:

A + B + C = 65

2B + B + (B+5) = 65

4B + 5 = 65

4B = 60

B = 16

Use B=16 and solve for the other two classes (dotted blue line).