Answer the following question.
Yuan is 7 years older than his brother David and twice his age. How old is David?
Step-by-step reasoning process: Let x be David's age. Yuan is seven years older than David, 7 + x = Y years. Yuan is also twice David's age, 2 * x = Y years. Since these two equations equal the same thing, we can write: 7 + x = 2 * x. Subtracting x from both sides we get 7 = x, so David is 7 years old.
The answer is 7.

Answer the following question.
The kids in Ms. Swanson's class have an average of 5 zits each. The kids in Mr. Jones' class have an average of six zits each. If there are 25 kids in Ms. Swanson's class and 32 in Mr. Jones' class, how many more zits are there in Mr. Jones' class than in Ms. Swanson's?
Step-by-step reasoning process: First find the total number of zits in Mr. Jones' class: 6 zits / kid * 32 kids = 192 zits. Then find the total number of zits in Ms. Swanson's class: 5 zits / kid * 25 kids = 125 zits. Then subtract the number of zits in Ms. Swanson's class from the number in Mr. Jones' class to find the difference: 192 zits - 125 zits = 67 zits.
The answer is 67.

Answer the following question.
Eddie is 92 years old. His granddaughter Becky is currently four times younger than he is. The mother of Becky - Irene, is two times her age. How old is Irene?
Step-by-step reasoning process: Becky is four times younger than Eddie, which means she is 92 / 4 = 23 years old. Her mother is two times older than she, so it means Irene is 23 * 2 = 46 years old.
The answer is 46.

Answer the following question.
Pauline has a garden with vegetables. In it, Pauline has planted 3 kinds of tomatoes - 5 of each kind, 5 kinds of cucumbers - 4 of each kind, and 30 potatoes. In the whole garden, there are 10 rows with 15 spaces in each to plant any vegetable. How many more vegetables could Pauline plant in her garden?
Step-by-step reasoning process: Pauline planted in total 3 * 5 = 15 tomatoes. Pauline also planted 5 * 4 = 20 cucumbers. In total Pauline planted 15 + 20 + 30 = 65 different vegetables. The whole garden can be filled up with 10 * 15 = 150 different vegetables. So Pauline could plant 150 - 65 = 85 more vegetables in her garden.
The answer is 85.