Question

5 beetles out of 45 insects.
1:9 is the answer

Answer 1

I suppose that this question is about ratios.

When we have A elements of one type, for every B elements of another type.

The ratio between these elements is A:B

In this particular case, we have:

5 beetles out of 45 insects (the 5 beetles do not belong to the group of 45 insects, if that where the case, we would not get the value 1:9 seen in the question)

Then there are 5 beetles and 45 insects.

The ratio is 5:45

Now, whit those we can divide both numbers by the same number and the ratio will be the same, then if we divide both by 5, we get:

(5/5):(45/5)

1:9