Answer:
50 Is the correct answer
Explanation:
Because 4/5 = 0.8 an if you divide 50 by 0.8. 50/0.8 = 40.
And he finished , and 40 questions in math 3 in science.
So he has a total of 50 questions in math.
Also cause I took the test and got it right. It said this was correct.