HARRIET BOUGHT CHRISTMAS CARDS.

SHE BOUGHT 1 BOX WITH 15 CARDS FOR $18.00,
1 BOX WITH 12 CARDS FOR 20.00, AND 2 BOXES WITH 10 CARDS FOR $8.00 EACH.
WHAT WAS THE AVERAGE PRICE SHE PAID PER CARD?

1 answer

18 + 20 + 16 = $54

15 + 12 + 10 + 10 = 47

54 / 47 = ?