There exists 3 pouches:

• The 1st has 5 blue marbles and 4 red marbles.
• The 2nd has 6 yellow marbles and 2 blue marbles.
• The 3rd has 3 red marbles and 7 yellow marbles.

The person to randomly selects a pouch and randomly selects a marble from it.

a) What is the probability that a person will select a yellow marble?

b) What is the probabliity that a person will select a blue marble?

c) What is the probability that a person will select a yellow marble from the 2nd pouch?