The senior class is collecting orders for graduation, So far, 54% have ordered their yearbook, 58% have ordered their gown and 15% have ordered their gown but not their yearbook. Find that probability that a randomly selected senior...
1. has ordered both a gown and a yearbook.
2. has ordered a yearbook or a gown.
3. has ordered neither a yearbook nor a gown.
4. has ordered a yearbook but not a gown.