Question

Mr. Finley’s class visited a number of freshwater lakes to learn more about the crocodiles and alligators living in them. The class counted the number of species in each lake as shown in the table.
Lake
Crocodiles
Alligators
A
4
5
B
21
35
C
3
9
D
6
16
E
24
30

The relationship between the number of crocodiles and the number of alligators is not proportional across all lakes. Only two of the lakes have crocodiles and alligators in the same proportion. Which two lakes are they?

lake A and lake B
lake B and lake C
lake A and lake E

lake C and lake D

Answer 1

Upon calculating, the correct answer among the choices listed above is lake A and lake E. Both lakes have the same proportion of the numbers of crocodiles and alligators.

In the lake A, there are 4 crocodiles and 5 alligators giving a ratio of 4:5
In the lake E, there are 24 crocodiles and 30 alligators giving a ratio of 24:30

Since 4:5 = 24:30, we will prove it.

First, we need to transform both ratios into fraction form to make it easier.

4/5 = 24/30

The next thing to do is to find their decimal forms by dividing their numerators to their respective denominators.

4 ÷ 5 = 0.8
24 ÷ 30 = 0.8

Thus, giving us:

0.8 = 0.8 ; Therefore, lake A and lake E are of the same proportion.