Small math problem, urgent~~~~ You don't have to talk about it in detail. You need to calculate the formula. You can talk about it! 1. A, B and C went to travel. A bought three bottles of coke, B bought two bottles of coke, and C didn't buy them. The three drank five bottles of coke on average. In order to bear the cost on average, how much should c give a if C took out five yuan? 2. My mother bought a bicycle for Xiao Liang. The price of Changfa supermarket, Dongfeng supermarket and shopping center is 230, but the price has changed due to the promotion in summer vacation Changfa Supermarket: 20% discount for all products Dongfeng Supermarket: 50 yuan for free when shopping at 200 yuan Shopping center: 10% off for all goods, 10 yuan free for bicycles over 100 yuan Where is the best place to buy? 3. There is a square cardboard. Cut a rectangle 3 decimeters wide from one side, and the area of the rectangle is measured to be 15 square decimeters. The remaining part needs to be cut out of the circle with the largest diameter. What is the area of the circle? How many can be cut out?

Small math problem, urgent~~~~ You don't have to talk about it in detail. You need to calculate the formula. You can talk about it! 1. A, B and C went to travel. A bought three bottles of coke, B bought two bottles of coke, and C didn't buy them. The three drank five bottles of coke on average. In order to bear the cost on average, how much should c give a if C took out five yuan? 2. My mother bought a bicycle for Xiao Liang. The price of Changfa supermarket, Dongfeng supermarket and shopping center is 230, but the price has changed due to the promotion in summer vacation Changfa Supermarket: 20% discount for all products Dongfeng Supermarket: 50 yuan for free when shopping at 200 yuan Shopping center: 10% off for all goods, 10 yuan free for bicycles over 100 yuan Where is the best place to buy? 3. There is a square cardboard. Cut a rectangle 3 decimeters wide from one side, and the area of the rectangle is measured to be 15 square decimeters. The remaining part needs to be cut out of the circle with the largest diameter. What is the area of the circle? How many can be cut out?

1.3 yuan, first calculate how much each 5 / (5 / 3) = 3 yuan, a used 9 yuan to buy Coke, B used 6 yuan, so C should give a 9-5 = 4 yuan. 2. Changfa Supermarket: 230 * 0.8 = 184 yuan, Dongfeng Supermarket: 230-50 = 180 yuan, shopping center: 230 * 0.9-20 = 187 yuan, so it is most suitable to buy in Dongfeng supermarket