Lizzy: Frankie and Carla played 30 games of ping pong against each other. Frankie won half as many games as did Carla. How many games did Carla win?.
Me: Hmmm, let me think. I think this is the detailed solution:
Let x be the number of games that Frankie won. Then the number of games Carla won would be 2 * x. And the sum of all the games would be x + 2 * x = 30 games. Thus, the expression simplifies to 3 * x = 30. And the value of x = 10 games. Therefore, the number of Carla's wins would be 2x = 20 games. Final answer: 20.