They have $27 for the party because 15 + 12 = <<15+12=27>>27
They have $12 for soda because 27 - 15 = <<27-15=12>>12
They can buy 4 bottles of soda because 12 / 3 = <<12/3=4>>4
They have 48 servings of soda because 4 x 12 = <<4*12=48>>48
Each guest gets 6 servings because 48 / 8 = <<48/8=6>>6
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