Answer:
A. 605 mL of the 35% solution
B. 55 mL of the 95% solution
Step-by-step explanation:
It is given that, you need 660 mL of a 40% alcohol solution. On hand, you have 35% alcohol mixture. You also have a 95% alcohol mixture.
Let x and y be the amount of 35% alcohol solution and 95% alcohol solution (in mL) respectively.
So,
Amount equation:
...(1)
Alcohol equation :
...(2)
On solving (1) and (2), we get
Now, substitute y=55 in (1).
Therefore, we need 605 mL of the 35% solution and 55 mL of the 95% solution.
Answer:
![[km^2]](https://tex.z-dn.net/?f=%5Bkm%5E2%5D)
Step-by-step explanation:
In this problem, the initial area of the forest at time t = 0 is

After every year, the area of the forest decreases by 9.8%: this means that the area of the forest every year is (100%-9.8%=90.2%) of the area of the previous year.
So for instance, after 1 year, the area is

After 2 years,

And so on. So, after t years, the area of the forest will be

And by substituting the value of A0, we can find an explicit expression:
![[km^2]](https://tex.z-dn.net/?f=%5Bkm%5E2%5D)
C is the answer to your question