Hey!

I'm sorry but if you don't mind I will answer the question in English.

Firstly, let's mark people from the question as symbols and write down what we know:

*Grandfather - ***G** Father - **F** Child - **C**We know that:

We assume that:

** 1 year = 12 months ≈ 52 weeks = 365 days**

** 1 week = 7 days**

**1 month** **≈ 4.25 weeks ****≈ 30 days**

Knowing that, we can make the following calculation:

We said that:

**1 week = 7 days** therefore, we can write:

It is not enough to solve the problem though, we need another part of the equation. Let's try with the grandfather:

Now we should bring everything to the same unknown -

**days** Let's try putting it together now:

| /20

I hope that it helps :)

Cheers!