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.