Answer:
Sarah answered 7 multiple choice questions and 3 free response questions correctly.
Step-by-step explanation:
Given that: she has 36 points.
          3 points each for the multiple choice question (MCQ)
          5 points each for the free response question (FRQ)
To determine how many of each question was answered correctly. Let the number of MCQ she answered be represented by x and FRQ by y.
 3x + 5y = 36  ............ 1
Since she answered a total of 10 question, then;
 x + y = 10
 x = 10 - y  ................  2
Substitute equation 2 into 1,
3(10 - y) + 5y = 36
30 - 3y + 5y = 36
2y = 6
y = 3
Substitute the value of y in equation 2,
x = 10 - y
 = 10 - 3
 = 7
x = 7, y = 3
Therefore, Sarah answered 7 multiple choice questions and 3 free response questions.
