Answer:
$22.50
Explanation:
First you have to add up $9.00 + $9.00 because it's 6 for $9.00 which is $18 and now you have 12 cantaloupes but since you need 15 you now divide 6 by 9.00 which gives you $1.50 which is the origanl price the cantaloupes were before and now you find the price of 3 cantaloupes 3x$1.50 = $4.50 now you add $18 + 4.50 = $22.50 :)