People get caffeine from a variety of sources: coffee, tea and caffeine soda. suppose that among adults, 55% drink coffee, 25% drink tea, and 45% drink soda. furthermore, 15% drink coffee and tea, 25% drink coffee and soda, 5% drink tea exclusively, and 5% drink all three beverage types.

solve for the following:
1. what percent of adults drink only coffee?
2. what percent of adults drink only soda?
3. what percent of adults drink none of the beverage types?