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 wor

th 3 credits did the student complete?

Let's denote the number of courses worth 3 credits as x, and the number of courses worth 4 credits as y.

Given:
x + y = 16 (total number of courses)
3x + 4y = 54 (total number of credits earned)

Now, we can solve these equations simultaneously to find the values of x and y.

From the first equation:
x = 16 - y

Substitute this expression for x into the second equation:
3(16 - y) + 4y = 54
48 - 3y + 4y = 54
48 + y = 54
y = 54 - 48
y = 6

Now, substitute the value of y back into the equation x = 16 - y:
x = 16 - 6
x = 10

Therefore, the student completed 10 courses worth 3 credits and 6 courses worth 4 credits.