Explanation:
Given that Cooper answered 28 questions correctly and 7 incorrect answers, If the total number of questions is x,
- let total number of questions be X,
therefore X = 28+7
= 35
- ratio of right answered questions to the total questions, R is
R =
![(28)/(35)](https://img.qammunity.org/2023/formulas/mathematics/high-school/nogv3dqv6zrnl9md4h0ng51tcum6scypsc.png)
=
![(4)/(5)](https://img.qammunity.org/2023/formulas/mathematics/high-school/svm48olph5an1udemt4a3hvizqbjvb4y4g.png)
therefore, the ratio is 4:5