A class is choosing a president, a vice president, and a treasurer. There are three students running for president: Maria, Ann, and Linda.
There are two students running for vice president: Bob and John.
There are two students running for treasurer: Jessica and Amanda.
The tree diagram below shows the possible outcomes. Use the diagram to answer the questions.

a) How many outcomes are there?

(b) How many outcomes have both John and Jessica being chosen?
(c) How many outcomes do not have Linda being chosen?