Brand x soda advertises, "we will give you 20% more soda than brand y for a total price that is 10% less than brand y's price! " what is the ratio of the unit price of brand x soda to the unit price of brand y soda? express your answer as a common fraction.

Let the amount of Brand Y = 1 kg.
Thus the amount of Brand X = (1 kg)(1.20) = 1.20 kg

Let the price of Brand Y = $1.
Thus the price of Brand X = ($1)(0.90) = $0.90.

Hence, the unit price of Brand X is $0.90 / 1.20 kg = $3/4 /kg and the unit
price of Brand Y is $1.00 / 1.00 kg = $1 /kg.

Therefore, the ratio of the unit prices is 3/4.