Ana, Beatriz and Carla enter an ice cream shop. Carla, who carries twice as much money as Beatriz, buys three ice creams of 90 cents each and now has twice as much money as Ana, but half as much as Beatriz.
On leaving, they find three cents on the ground and so they can return all three on the bus.
How much does the bus ticket cost?
The difference between the double of Beatriz's money and half of what Beatriz has is the price of the three ice creams, that is 270 cents, so we have the following equation:
cents Beatriz has 180 cents, Carla has 90 cents left and Ana has 45 cents. In total they have 315 cents so if they find 3 cents, they have a total of 318 cents and therefore each bus ticket costs 318/3 = 106 cents.