In a zoo, 21% of the animals are reptiles and 11% are birds. There are a total of 1,500 animals in the zoo. Which proportion can be solved for r, the number of reptiles?

A. 21/100 = r/1,500
B. 11/21 = r/1,500
C. 11/100 = r/1,500
D. 100/21 = r/1,500

I'm not that good with percents. All I would like is some help, not answers, but just something to help me solve this.

21 % = 21 parts of 100

oh... So its like fractions?

Yes, many percents can be expressed as fractions.

Ok, thank you so much! Now it makes a lot of sense.

You are welcome.

To solve this problem, we need to use proportions. Proportions are equations that state that two ratios are equal.

In this case, we are given that:
- 21% of the animals are reptiles, which is the same as saying that 21 out of 100 animals are reptiles.
- There are a total of 1,500 animals in the zoo.

Let's set up a proportion to solve for the number of reptiles, r.

The proportion can be written as follows:
(21 reptiles)/(100 total animals) = r reptiles/1,500 total animals

Simplifying this proportion, we have:
21/100 = r/1,500

Now we can match this proportion with the given options.

A. 21/100 = r/1,500
B. 11/21 = r/1,500
C. 11/100 = r/1,500
D. 100/21 = r/1,500

Comparing the given proportion with the options, we can see that option A matches our proportion:
21/100 = r/1,500

Therefore, the correct proportion to solve for the number of reptiles, r, is option A.