Please help me I'm going to fail if you don't help me

how many grams each of a 10% salt solution and a 5% salt solution must be mixed in order to obtain 400g of an 8% solution?

Brrunno [24]

I dont want to give you the exact equation so u wont be copying- here is an example.

let x=grams of salt that you already have

let y=grams of salt that need to be added

let z=total amount of salt in the solution after adding salt

We know that salt makes up 25% of the 400g solution, and that 25% can also be written as .25. Thus, we can write an equation to determine x's value:

x=.25*400g

x=100g

Therefore, there are 100 grams of salt already in the solution.

Now that we've determined x's value, we'll bring z into the equation. There are two ways to calculate z. z is equivalent to the sum of x and y. Remember, x is equal to 100 grams. So, z's equation is as follows:

z=100g+y

The other way to calculate z is as a percentage of the final solution. As the question states, we want the final solution to have a salt content of 40% (which we can write as .40). The final amount of solution can be written as below:

400g+y=total amount of solution after adding salt.

This is because we are adding y (the amount of salt needed to bring the salt content to 40 percent)to the amount of solution which we already have.

Therefore, the second way to express z is below:

z=.40*(400g+y)

After we have two equations for z, we can set them equal to each other as follows:

100g+y=.40*(400g+y)

We then can distribute the .40 over the parenthesis.

100g+y=160g+.40y

And then we can subtract 100 grams from both sides of the equation.

y=60g+.40y

Next, we subtract .40 y from both sides of the equation to get y on one side.

.6y=60g

Finally, we can divide both sides by .6 to isolate y.

y=100g

Therefore, you must add 100g of salt to the solution to make it 40 percent salt.

DID I DO IT RIGHTT?? pls tell me

7 0

3 years ago

Assignment: Compound Interest Investigation

sukhopar [10]

To help Tyler better understand how his money will increase in an account that uses simple interest and one that uses compound interest, we are going to use two formulas: a simple interest formula for the accounts that use simple interest, and a compound interest formula for the accounts that use compound interest.
- Simple interest formula: $A=P(1+rt)$
where:
$A$ is the final investment value
$P$ is the initial investment
$r$ is the interest rate in decimal form
$t$ is number of years
- Compound interest formula: $A=P(1+ \frac{r}{n} )^{nt}$
where:
$A$ is the final investment value
$P$ is the initial investment
$r$ is the interest rate in decimal form
$t$ is he number of years
$n$ is the number of times the interest is compounded per year

1.
a. This is a compound interest account, so we are going to use our compound interest formula. We now that $P=1500$ , $t=5$ , and since the interest is compounded annually (1 time a year), $n=1$ . To find the interest rate in decimal form, we are going to divide it by 100%: $r= \frac{4}{100} =0.04$ . Now that we have all the values lets replace them in our compound interest formula:
$A=1500(1+ \frac{0.04}{1}) ^{(1)(5)}$
$A=1824.98$
We can conclude that after 5 years he will have $1824.98 in this account.
b. Here we will use our simple interest formula. We know that $P=1500$ , $t=5$ , and $r= \frac{4}{100} =0.04$ . Lets replace those values in our simple interest formula:
$A=1500(1+(0.04)(5))$
$A=1800$
We can conclude that after 5 years he will have $1800 in this account.
c. The compound interest account from point a will yield more money than the simple account one from point b. The difference between the tow amounts is $1824.98-1800=24.98$

2.
a. Here we are going to use our compound interest formula. We know that $P=2000$ , $t=1$ and $r= \frac{8}{100} =0.08$ . We also know that the interest is compounded Quaternary (4 times per year), so $n=4$ . Now that we have all our values lets replace them into our formula:
$A=2000(1+ \frac{0.08}{4} )^{(4)(1)}$
$A=2164.86$
We can conclude that after 1 year he will have $2164.86 in this account.
b. Here we are going to use our simple interest formula. We know that $P=2000$ , $t=1$ , and $r= \frac{8}{100} =0.08$ . Once again, lets replace those values in our formula:
$A=2000(1+(0.08)(1))$
$A=2160$
We can conclude that after 1 year he will have $2160 in this account.
c. The compound interest account from point a will yield more money than the simple account one from point b. The difference between the tow amounts is $2164.86-2160=4.86$

3.
a. Since Bank A offers an account with a simple interest, we are going to use our simple interest formula. From the question we know that $P=3200$ , $t=3$ , and $r= \frac{3.5}{100} =0.035$ . Now we can replace those values into our formula to get:
$A=3200(1+(0.035)(3))$
$A=3536$
Now, to find the interest earned for Bank A we are going to subtract $P$ from $A$
$InterestEarned=3536-3200=336$
We can conclude that the interest earned for Bank A is $336
b. Since Bank B offers an account with a compound interest, we are going to use our compound interest formula. We know that $P=3200$ , $t=3$ , $r= \frac{3.4}{100} =0.034$ , and since the interest is compounded annually (1 time a year), $n=1$ . Now that we have all the values, lets replace them in our formula to get:
$A=3200(1+ \frac{0.034}{1} )^{(1)(3)}$
$A=3537.62$
Now, to find the interest earned for Bank A we are going to subtract $P$ from $A$ :
$InterestEarned=3537.62-3200=337.62$
We can conclude that the interest earned for Bank B is $337.62
c. Even tough the interest returns between the tow Banks are very similar, Bank B offers a slightly better interest over a period of time, which can make a big difference in the long run. If Tyler wants the earn more money, he definitively should deposit his money in Bank B.
d. The compound interest account from Bank B will yield more money than the simple account one from Bank A The difference between the tow amounts is $3537.62-3536=1.62$

6 0

4 years ago

Deb borrows 6,300 for one year at 9.75% how much will she pay back at the end of the loan term

Step2247 [10]

Answer:

The correct answer is that Deb will have to pay US$ 6,914.25 at the end of the loan.

Step-by-step explanation:

Loan in US$: 6,300

Term: One Year

Interest rate: 9.75% annually

1. Let's calculate how much money Deb will pay in interests for the loan:

Loan * Interest rate * Term