1. **State the problem:** Find how many boys in a class of 20 are simultaneously tall, play soccer, wear watches, and wear brown shoes. 2. **Given data:** - Total boys: 20 - Brown shoes: 14 - Watches: 12 - Soccer team: 11 - Tall: 10 3. **Key concept:** To find the number of boys who satisfy all four conditions, we use the principle that the maximum number of boys in all groups cannot exceed the smallest group size. 4. Since each condition must be met simultaneously, the maximum number of boys who are tall, play soccer, wear watches, and wear brown shoes is limited by the smallest group size. 5. The smallest group size is 10 (tall boys). 6. Therefore, the maximum number of boys who could be tall, soccer-playing, watch-wearing, and brown-shoe-wearing is: $$\boxed{10}$$ This is because you cannot have more boys meeting all four criteria than the smallest group size among those criteria.