On Sunday, Xiao Ming and seven classmates, a total of 8 people, went on an outing. On the way, he spent 20 yuan to buy drinks. The store only had coke and milk tea. It is known that coke costs 2 yuan a cup and milk tea costs 3 yuan a cup. If 20 yuan is just used up. (1) how many ways to buy? How many cups of cola and milk tea in each way? (2) When each person has at least one drink and at least two milk teas, how many ways to buy them?

On Sunday, Xiao Ming and seven classmates, a total of 8 people, went on an outing. On the way, he spent 20 yuan to buy drinks. The store only had coke and milk tea. It is known that coke costs 2 yuan a cup and milk tea costs 3 yuan a cup. If 20 yuan is just used up. (1) how many ways to buy? How many cups of cola and milk tea in each way? (2) When each person has at least one drink and at least two milk teas, how many ways to buy them?

(1) Let's buy Coke and milk tea as X and Y cups respectively. According to the meaning of the question, we get 2x + 3Y = 20 (and X and y are natural numbers) 2x = 20-3y, x = 10-32y  x = 10Y = 0, x = 7Y = 2, x = 4Y = 4, x = 1y = 6. So there are four ways to buy Coke and milk tea. The number of cups in each way is ① 10, 0; ② 7, 2; ③ 4, 4; ④ 1

On Sunday, Xiao Ming and seven classmates, a total of 8 people, went on an outing. On the way, he spent 20 yuan to buy drinks. The store only had coke and milk tea. It is known that coke costs 2 yuan a cup and milk tea costs 3 yuan a cup. If 20 yuan is just used up. (1) how many ways to buy? How many cups of cola and milk tea in each way? (2) When each person has at least one drink and at least two milk teas, how many ways to buy them?

(1) Let's buy Coke and milk tea as X and Y cups respectively. According to the meaning of the question, we get 2x + 3Y = 20 (and X and y are natural numbers) 2x = 20-3y, x = 10-32y ∧ x = 10Y = 0, x = 7Y = 2, x = 4Y = 4, x = 1y = 6. So there are four ways to buy Coke and milk tea. The number of cups of coke and milk tea in each way is ① 10, 0; ② 7, 2; ③ 4, 4; ④ 1, 6; (2) according to the meaning of the question, when each person has at least one drink and milk tea has at least two cups According to (1), there are two ways to buy: ① 7, 2; ② 4, 4

On Sunday, Xiao Ming and seven classmates went on an outing together. On the way, he spent 20 yuan to buy drinks. The store only had coke and milk tea. It is known that coke costs 2 yuan for a cup and milk tea costs 3 yuan for a cup. If 20 yuan is just used up, there are several ways to buy them. How many cups of each way and milk tea?

The most original method: milk tea from scratch, a cup of a cup of test, to meet the conditions of the combination left
Binary linear equation: let's buy Coke x cup, milk tea y cup. The equation 2x + 3Y = 20 ①；x+y=8…… ②.
In theory, if we do not consider the number of people, there are multiple choices, but if we ask for just one cup, there is only one answer, x = 4, y = 4