Grammatically help needed question?

[hailam]

Do you think this sentence has any grammatical mistakes?
"how many of us know how to wash our hair?"

[SirGod]

*Not a teacher

How many of us know how to wash their hair?

[hailam]

*Not a teacher

How many of us know how to wash their hair?

Why should I use "their" instead of our? can you explain?

Thanks

[Karima-19]

Why should I use "their" instead of our? can you explain?

Thanks

Not a teacher!
How many of us know how to wash their hair? Is the correct sentence gramatically. And you have to use "their" instead of "us"...I'm going to explain for you why: (Look at these examples)

1- We have some books 2- The books are for us 3- These are our books

Now let's come back to your example:

We have hair, this hair is for us, this is our hair.

When you said in your sentence "us", you use it as object
(accusative and dative), and you must use"our" as (Possessive determiners).

Hope it gonna help you!

[5jj]

"How many of us know how to wash our hair?"

That seems to me to be acceptable.

[Rover_KE]

"How many of us know how to wash our hair?"

As 5jj said, that is correct.

You can ignore the other answers, hailam.

Rover

[bhaisahab]

As 5jj said, that is correct.

You can ignore the other answers, hailam.

Rover

I agree.