A college student completed some courses worth 3 credits and some courses worth 4 credits. The student earned a total of 54 credits after completing a total of 16 courses. How many courses worth 3 credits did the student complete?

Answer 1

Let's say the student completed x courses worth 3 credits and y courses worth 4 credits.

According to the information given:

Total number of courses completed: x + y = 16 ....(1)

Total number of credits earned: 3x + 4y = 54 ....(2)

Now, we need to solve these two equations simultaneously.

Multiplying equation 1 by 3, we get:

3x + 3y = 48

Subtracting this equation from equation 2, we get:

3x + 4y - (3x + 3y) = 54 - 48

y = 6

Substitute the value of y back into equation 1:

x + 6 = 16

x = 10

Therefore, the student completed 10 courses worth 3 credits.