Question

Each course at Mt. Regis College is worth either 3 or 4 credits. The members of the men's swim team are taking a total of 48 courses that are worth a total of 155 credits. How many 3-credit courses and how many 4-credit courses are being taken

Answer 1

3 Credit Courses = 37

4 Credit Courses = 11

Explanation:

1. Set up 2 equations:

3x + 4y = 155

x + y = 48

2. Simplify the second expression for x by subtracting y from both sides

x = 48 - y

3. Substitute 48 - y for x

3(48-y) + 4y = 155

4. Simplify the expression by multiplying by 3

144 - 3y +4y = 155

5. Subtract 144 from both sides and subtract 3y from 4y

y = 11 = 4 Credit Courses

6. Substitute y for equation 2

x = 48-11

7. solve for x

x = 37 = 3 Credit Courses