Indicate any three numbers proportional to the numbers 1, 4 and 5.

First, let’s write down the general view of all sets of three numbers proportional to the numbers 1, 4 and 5.

Let a denote the smallest number of such a triplet of numbers.

Since these three numbers must be proportional to the numbers 1, 4 and 5, the smallest number of these three numbers must be equal to a, and the other two numbers must be equal to 4a and 5a, respectively.

Therefore, the general view of a set of three numbers proportional to the numbers 1, 4 and 5 is a, 4a and 5a, where a is some integer.

Choosing different values ​​for the parameter a, we get different sets of three numbers, proportional to the numbers 1, 4 and 5.

For example, with a = 7 we get 7, 4 * 7 = 28, 7 * 5 = 35.

Answer: 7, 28 and 35.