There were 3 * 120 = 360 calories in the package. So he ate 360 / 2 = 180 calories.
The answer: 180
Reverse engineering the question: A package of candy has 3 servings with 120 calories each. John eats half the package. How many calories did he eat?

One week is 7 days, so for one week, Mike trained for 7 * 2 = 14 hours. The second week he began to train for 3 hours a day, so he trained for 7 * 3 = 21 hours. That means Mike in total trained for 21 + 14 = 35 hours.
The answer: 35
Reverse engineering the question: Mike began to train to play basketball every day for a tournament. One day he plays a maximum of 2 hours. After a week of training, he increased the maximum time to 3 hours. How many hours did Mike train during the first two weeks?

Let x represent the number of passes thrown to the left side of the field. Right:2x. Center:x + 2. Total:x + 2x + x + 2 = 50. 4x + 2 = 50. 4x = 48. x = 12 passes.
The answer: 12
Reverse engineering the question: A quarterback throws 50 passes in one game. He throws twice as many passes to the right of the field than he does to the left of the field. He throws 2 more passes to the center of the field than he did to the left. How many passes did he throw to the left side of the field?

The two t - shirts amount to $8 x 2 = $16. The two bags amount to $10 x 2 = $20. So Timothy spent $16 + $20 = $36 for the shirts and bags. He still has $50 - $36 = $14 left to spend for the key chains. With the money, he can buy $14 / $2 = 7 sets of key chains. Therefore, he can buy 7 x 3 = 21 pieces of key chains.
The answer: 21
Reverse engineering the question:
Timothy has $50 to spend at a souvenir shop. He sees some t-shirts that cost $8 each, key chains that sell 3 pieces for $2, and bags that cost $10 each. Timothy buys 2 t-shirts and 2 bags. How many pieces of key chains can he buy with the amount of money he has left?