How do i find the information that one of my kids entered when he created an email account ?

one of my kids created an yahoo email account but has forgotten the security questions they entered (i.e. date of birth %26amp; zip code) and now he can't access the account. I've tried entering his birthdate and the zip code we had when he created the account,and nothing matches. How do I get the account information so he can access his account?

How do i find the information that one of my kids entered when he created an email account ?
You need to know the email address and password or secret information otherwise there is nothing that can be done.