A box of tulip bulbs contains six bulbs that produce yellow flowers and five bulbs that produce

Question:

A box of tulip bulbs contains six bulbs that produce yellow flowers and five bulbs that produce red flowers. Four bulbs are to be randomly selected without replacement. Find the probability that:
(a) Exactly two of the selected bulbs produce red flowers.
(b) At least two of the selected bulbs produce red flowers.
(c) All four selected bulbs produce flowers of an identical color.