portfolio for internship

i am applying for an internship and the firm has requested a portfolio. how many projects should i send them and how detailed should i be with each project?

i have seen people here talk about teasers - but i do not understand if a teaser is solicited or not so i am not sure if my question has already been answered. i am thinking of sending about 5 projects (one per page) - one sculptural piece, 3 products, and 1 piece of furniture. i have many more projects but i am hesitant to include 20 pages and overwhelm the reviewer. some of my projects are not ideal anyway - for instance, a great idea lacking great form, a wonderful concept substantiated only with sketches and not a model, some interesting sculptures that may slant my porfolioto the fine arts side, and a conceptual environments that spans several pages. maybe i should include the products that have solid concepts but not ideal forms?? i am proud of the ideas but worried that the form will work against me.

what are your thoughts?