How do i respond to cuantas personas hay en tu familia?

The question asks, "How many friends do you have? The answer, of course, is up to you. You may pick a number and respond, "Tengo __________ amigos," which means, "I have ______ friends." You need to fill in the blank with an appropriate number. When you say 'amigos' it is understood that you mean friends of both genders. If you want to indicate the number of female friends you have, then you have to use the Word 'amigas.'