Hello, Zshan96!

In a house there live 27 people.

One man eats 4 bread, a woman eats 3 bread, and a child eats half a bread.

Every day 63 breads are eaten.

How many men, women and children are living in that house?

Let: .

We have: .

And: .

Subtract [2] - [1]: .

. .

Since is an integer, must be a multiple of 5.

That is: . , for some integer

. .

Since is a positive integer, must be a negative even number.

The first time this happens is: .

Substitute into [4]: .

Substitute into [3]: .

Substitute into [1]: .