Answer:
its 2
Step-by-step explanation:
x = liters of 20% solution
Mixing the 20% solution with the 60 L of 90% solution gives a new mixture with volume (x + 60) L. Each L of the 20% solution contributes 0.2 L of alcohol and thus a total of 0.2x L of alcohol, while the 60 L of 90% solution contributes 54 L of alcohol.
We want the concentration of the new mixture to be 80%, so we require

Solve for x:



So you will need 30 L of the 20% solution.
<h2>
Answer:</h2><h2>The chance is 100 % since we have not seen it in the past three days.</h2>
Step-by-step explanation:
The odds of seeing a black cat are 25% every day.
It also means that the possibility of seeing a black cat is once in 4 days, since 25%
Given, we have not seen one black cat in 3 days.
The chance of seeing a black cat on the 4th day = ?
= 100 % since we have not seen it in the past three days.
54/x = 6...multiply both sides by x
54 = 6x...divide both sides by 6
54/6 = x
9 = x