A glass of 320 grams of pure milk, I drank 1 / 4 for the first time, and then drank 1 / 4 after filling with water. How many grams of pure milk did I drink for the second time? How do I do it? Why do you do this? Explain why

A glass of 320 grams of pure milk, I drank 1 / 4 for the first time, and then drank 1 / 4 after filling with water. How many grams of pure milk did I drink for the second time? How do I do it? Why do you do this? Explain why

For the first time: 320 * 4 / 1 = 80 (g) for the second time: 320 * (1-4 / 1) * 4 / 1 = 60 (g) because the amount of milk remains unchanged, no matter how much water is added, or 4 / 1 of the total amount of 4 / 3 is drunk, so 60

A glass of pure milk 320 grams, Wang Hua first drink a quarter, and then drink a quarter full of water
Which time did Wang Hua drink more pure milk? How many grams of pure milk did he drink the second time?

First time more
Pure milk for the first time = 320 * 1 / 4 = 80
Pure milk for the second time = (320-80) * 1 / 4 = 60

Li Lin drank 16 of a glass of milk, then filled it with water, drank another 13 of a glass, then filled it with water, drank another half of it, then filled it with water, and finally drank all of it. So Li Lin drank more milk or water? （　　）
A. As much B. water as much C. milk as much D. not sure

16 + 13 + 12 = 1, that is, drink as much water as milk

A box of milk has (10 / 9) liters. Parents and Xiao Ming drank (3 / 1), (9 / 2) and (9 / 4) of the milk respectively. How many liters did they drink respectively

10 / 9 * 3 / 1 = 10 / 3 (L) 10 / 9 * 9 / 2 = 5 / 1 (L) 10 / 9 * 9 / 4 = 5 / 2 (L) the total is gone---