Answer:
Option C. 
Step-by-step explanation:
we know that
![A=\frac{P[(1+r)^{n} -1]}{r(1+r)^{n}}](https://tex.z-dn.net/?f=A%3D%5Cfrac%7BP%5B%281%2Br%29%5E%7Bn%7D%20-1%5D%7D%7Br%281%2Br%29%5E%7Bn%7D%7D)
we have
substitute in the formula
![A=\frac{400[(1+0.00625)^{72} -1]}{0.00625(1+0.00625)^{72}}\\ \\A=\frac{226.446972}{0.009788}\\ \\A=\$23,134.61](https://tex.z-dn.net/?f=A%3D%5Cfrac%7B400%5B%281%2B0.00625%29%5E%7B72%7D%20-1%5D%7D%7B0.00625%281%2B0.00625%29%5E%7B72%7D%7D%5C%5C%20%5C%5CA%3D%5Cfrac%7B226.446972%7D%7B0.009788%7D%5C%5C%20%5C%5CA%3D%5C%2423%2C134.61)
Answer:
not sure
Step-by-step explanation:
What is her answer? She needs to have an answer. If she doesn't have an answer, then I can't identify the mistake
x = quarts of 30% acid solution
y = quarts of 65% solution
x + y = 175
Each quart of the 30% solution contributes 0.30x quarts of acid; similarly, each quart of the 65% solution contributes 0.65y quarts of acid. So
0.3x + 0.65y = 0.55*175 = 96.25
That is, the chemist wants 175 quarts of a new mixture with a 55% concentration of acid, which comes out to 95.25 total quarts of acid. The total amounts of acid from either sides of this equation must balance out.
Now solve for x and y:
x + y = 175 ==> y = 175 - x
0.3x + 0.65y = 96.25 ==> 0.3x + 0.65(175 - x) = 96.25
==> 0.3x + 113.75 - 0.65x = 96.25
==> 17.5 = 0.35x
==> x = 50 ==> y = 125
