1. There are 12 houses on a street. Each house is a single-story, 2-story, or 3-story home. We will ignore access to basements and attics for this problem. No home has multiple staircases either. If 1/3 of the homes have exactly 2 stories and 1/4 of the homes are single-story houses, how many flights of stairs are inside the houses on the street altogether? _______ flights of stairs *