Final answer:
The ratio of math books to English books ordered by the teacher is 5:3, after simplifying the actual count of 20 math books and 12 English books by their greatest common divisor, which is 4.
Step-by-step explanation:
The ratio of math books to English books that the teacher ordered is calculated by comparing the number of each type. The teacher ordered 20 math books and 12 English books. To find the ratio, we divide both numbers by the greatest common divisor of the two quantities to simplify the ratio. In this case, the greatest common divisor of 20 and 12 is 4:
- 20 math books ÷ 4 = 5
- 12 English books ÷ 4 = 3
Therefore, the simplified ratio of math books to English books is 5:3.