You mix soda water, fruit punch concentrate, and ginger ale in the ratio of 1 : 2 : 5 to make fruit punch. How many pints of each ingredient should you use to make 4 gallons of fruit punch?

Answer 1

soda water : fruit punch : ginger ale = 1:2:5 = x : 2x : 5x

x+2x+5x = 4
8x = 4
x = 1/2

so 1/2 gallons of soda water
1 gallon of fruit punch concentrate
2.5 gallons of ginger ale

check:
1/2 : 1 : 5/2 = 1 : 2 : 5
1/2 + 1 + 5/2 = 4

all is good