Answer :

Well, if she has 6 half dollars, that is 6 coins.
If she has 3 dollar coins, that is 3 coins. 
altogether that is 9 coins.

are you sure you worded the question right because that was really easy

Answer with explanation:

Number of half Dollars in Sari's Bag= 6 Half Dollars

1 Half Dollar =50 cents=1 coin

or, 6 Half Dollars =3 Dollars

It means there are 6 cents in Sari's Bag or 3 Dollars in the Sari's bag.

Total Number of Coins in Sari's Bag=(3 Dollar coins+3 Dollar coins)or (3 Dollar coins+ 6 Cents coins)

⇒→Total Mass of the coins in Sari's Bag=Mass of (3 Dollar coins+6 Cent coin) or Mass of (3 Dollar coins+3 Dollar coins)

=Mass of (3 Dollar coins+6 Cent coins) or Mass of (6 Dollar coins)