Answer:
If he got 9 out of 15 correct, he got 6 problems incorrect.
6/15 is incorrect
6/15 × 100
40 % is your answer
40% are incorrect
Explanation:
If 9 are correct then 15-9 = 6
6 are incorrect
6/15 = 2/5
Change to a percent
2/5 *20/20 = 40/100
Percent means out of 100
5.2m questions
6.7m answers