Final answer:
If you score 90% on an assignment, the ratio of correct questions to total questions is 9:10.
Step-by-step explanation:
The ratio of correct questions to total questions can be calculated by dividing the number of correct questions by the total number of questions and then multiplying by 100 to express it as a percentage. In this case, if you score 90% on an assignment, it means you answered 90 out of 100 questions correctly. So, the ratio of correct questions to total questions is 90:100 or simply 9:10.