Respuesta :

Aqui esta tu cuaderno. Donde lo pongo?
You need to use lo because cuaderno is masculine and singular form. 

For this case we have an answer and what we should do is to ask the right question to receive that answer.

The answer is:

Here's your notebook

The question you must ask is:

Where is my notebook?

The translation of the question in Spanish is:

¿Dónde está mi cuaderno?

Answer:

The question you must ask is:

¿Dónde está mi cuaderno?

The answer is:

Aquí está tu cuaderno