Hey guys I Really really need help with an sql query. Apparently I'm missing some big concept and can't figure it out.

There are three tables:

Customer(cust_num, phone, address)
Menu( food_name, food_type, price)
Orders( cust_num, food_name, quantity)

I need to find the phone number of each customer who ordered some food with food type 'soup' and ordered three hamburgers.

So, what I think I should be doing is: Query for customers who have ordered some soup (which I know how to do), then query for customers who have ordered three hamburgers (which I know how to do) and then inner join these two resulting tables.

I can't figure out how to inner-join two queries though =/. Is there a better way I should be doing this? Please help me, thank you!

select DISTINCT a.cust_num, a.phone from customer a 
inner join orders b on a.cust_num=b.cust_num 
inner join menu c on c.food_name=b.food_name
where c.food_type='SOUP' OR (b.food_name='hamburgers' and b.quantity=3)