A money box contains four $2 coins, seven $1
coins, twelve 50 cent coins and twenty two 20
cent coins. Christie chooses a coin at random.
Find the probability she chooses a coin that
is worth at most $1.

Find the probability she chooses a coin
that is either a $1 or a $2 coin.

Find the probability she chooses a coin
that is worth at least 50 cents.

Part #1:  13/15

Part #2:  11/45

Part #3:  23/45

Step-by-step explanation:

Part #1:  So add the total amount of coins:  4 + 7 + 12 + 22 = 45

Since the only coins that are at most $1 are:  The $1 coins, 50 cent coins, and the 20 cent coins.  That is a total of 7 + 12 + 20 = 39

39/45

13/15

 13/15

Part #2:  Since the only coins that are $1 or $2:  The $1 coins and the $2 coins.  That is a total of 4 + 7 = 11

11/45

 11/45

Part #3:  Since the only coins that are at least 50 cents:  The $1 coins and the $2 coins and the 50 cent coins.  That is a total of 4 + 7 + 12 = 23

23/45

 23/45