CPM Homework Help : CC2 Problem 9-41

Thu has a bag with $7$ green marbles, $5$ blue marbles, and $4$ red marbles. For each part below, if the marble selected is replaced before the next marble is drawn, what is the probability that she will draw.

A red marble?
Hint (a):
Remember that probability can be written as a fraction:
$\frac{\text{# of red marbles}} {\text{Total # of marbles}}$
More Help (a):
How many red marbles are there?
How many total marbles?

A red or a green marble?
Hint (b):
See part (a).
Answer (b):
$\frac{11}{16}$

An orange marble?
Hint (c):
See part (a).