Answer:
If there are 4 adults and 12 children the ratio of adults to children can be written as 4:12. 4 and 12 are both divisible by (able to be divided by) 4, so 4:12 can be simplified by dividing the number of children and adults by 4. 4 divided by 4 equals 1 and 12 divided by 4 is 3, meaning 4:12 simplifies to 1:3. If there is 1 adult and 3 children there is a total of 4 people in that ratio. Since the problem asks how many children are at the zoo if there are 60 people in total we need to multiply 1:3 by 20. 1 times 20 equals 20, and 3 times 20 equals 60. So our ratio is now 20:60 or 20 adults to 60 children. We can check by adding up the adults, and children, which as the problem asks adds up to 80 people.
