Answer:

Step-by-step explanation:
Let  equal the number of questions.
 equal the number of questions.
Let's find how many total questions there are:

Divide by the coefficient of  , which in this case is
, which in this case is 

So we have a total of  questions, each are worth
 questions, each are worth  points.
 points.
Now, Gianna got  questions wrong, and if we know there are
 questions wrong, and if we know there are  total questions...
 total questions...

Solve.

So we know Gianna got  questions correct.
 questions correct.
Let's use an expression to figure out her score. 
Again, let  equal the number of questions.
 equal the number of questions.

Substitute.

Multiply.
