How to generate questions based on response to previous question?

I want to ask name, address, phone number based on the response to a previous question.  For example, if someone says he/she has 3 children, I want to ask name, address, and phone for each of the three children.

Also, can I make those one question, instead of 3 questions?

You can do it by using conditions, by showing fields depending on the input given on the how many children textbox. But it would require a lot of work as someone may have more than 10 children, and manually adding these conditions and fields would take so much time.

What I recommend you to implement this is to use "Configurable List" widget. You can define various field types and multiply them with it. I made an example form for you by using that widget:

https://www.jotform.com/81472106323953 

As you see, when a user clicks add more children button, field automatically duplicates itself.

About how to add a widget to your form, you can check this guide:

How to Add a Widget to Your Form

For more information about configurable list widget: 

How to Set Up the Configurable List Widget

Hope it helps! Feel free to contact us again if you need any further assistance.