There are several liters of 55% alcohol. After adding one liter of 80% alcohol, the concentration becomes 60%. To get 75% alcohol, 80% alcohol is needed. How many liters of 80% alcohol are needed to get 75% alcohol?

There are several liters of 55% alcohol. After adding one liter of 80% alcohol, the concentration becomes 60%. To get 75% alcohol, 80% alcohol is needed. How many liters of 80% alcohol are needed to get 75% alcohol?

Let x rise
Alcohol 55% X
Plus 1
Then 55% x + 1 * 80% = 60% (x + 1)
0.55x+0.8=0.6x+0.6
0.05x=0.2
x=4
Let y be added
That's 4 + y liters
Alcohol is 4 * 55% + 80% y = 75% (y + 4)
2.2+0.8y=0.75y+3
0.05y=0.8
y=16
A: add 16 liters

Mix 80% and 20% alcohol solution to make 150 kg of 60% alcohol solution. How many kg of these two alcohol solutions
What do mathematical geniuses do

The ratio of 80% 2 to 0% is (0.6-0.2): (0.8-0.6) = 2:1
So 80% of 150 △ 3 × 2 = 100 kg is needed
20% of 150-100 = 50 kg
Hope to help you, I use a mobile phone, can not receive follow-up, if you have any questions, please send me a message~

How many centimeters does one inch equal? How do you calculate the TV inch?

One inch is equal to 3.3333... Cm. The TV inch is measured by the diagonal size of the TV screen