Question 187642This question is from textbook
: I really need help can anyone help meHI I had 3 more problems; Due Monday I did do a lot of them will you please help me
1. An investor has three investments which pay 3%, 5% and 8%, respectively. He has three times as much invested at 5% than at 3% and$ 600 more invested at 8% than at 3%, if the total interest from the investment after 1year is $854, how much was invested at 5%?
2. A solution problem: How many ounces of a 25% solution must be added to 40 ounces of a 7% saline solution to make a 15% saline solution?
3. How many cups of party mix that is 69% pretzels must be added to 120 cups of a party mix that is 45% pretzels to make a party mix that is 54% pretzels?
4. A merchant has coffee worth $30 a pound that she wishes to mix with 90 pounds of coffee worth $90 a pound to get a mixture that can be sold for $70 a pound how many pounds of $30 coffee should be used?
5. If three times the smaller of two consecutive integers is added to four times the larger, the result is 116. Find the smaller integer. ( my answer was 16) I hope that was right will you please check it for me Thanks for your help! Sonya
please?
This question is from textbook
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! You have submitted quite a few problems here. I will do the first one and give
you the equations for the rest. You can email me if you have difficulty.
:
1. An investor has three investments which pay 3%, 5% and 8%, respectively.
He has three times as much invested at 5% than at 3% and$ 600 more invested
at 8% than at 3%, if the total interest from the investment after 1 year is
$854, how much was invested at 5%?
:
Let x = amt invested at 3%
then
3x = amt invested at 5%
and
(x+600) - amt invested at 8%
;
Write a total interest equation:
.03x + .05(3x) + .08(x+600 ) = 854
.03x + .15x + .08x + 48 = 854
.26x = 854 - 48
x = 
x = $3100 invested at 3%
and
2(3100) = $9300 invested at 5%
:
:
2. A solution problem: How many ounces of a 25% solution must be added to 40 ounces of a 7% saline solution to make a 15% saline solution?
:
Let x = amt of 25% solution required
then
(x+40) = resulting amt:
:
.07(40) + .25(x) = .15(x+40)
:
:
3. How many cups of party mix that is 69% pretzels must be added to 120 cups of a party mix that is 45% pretzels to make a party mix that is 54% pretzels?
:
let x = 69% mix
then
(x+120) = resulting amt
:
.69x + .45(120) = .54(x+120)
:
:
4. A merchant has coffee worth $30 a pound that she wishes to mix with 90 pounds of coffee worth $90 a pound to get a mixture that can be sold for $70 a pound how many pounds of $30 coffee should be used?
:
Let x = amt of $30 coffee required
then
(x+90) = resulting amt
:
30x + 90(90) = 70(x+90)
;
:
5. If three times the smaller of two consecutive integers is added to four times the larger, the result is 116. Find the smaller integer.
:
Two consecutive integers: x, (x+1)
:
3x + 4(x+1) = 116
;
The answer is indeed, 16, way to go, substitute 16 for x in the equation to
prove it to yourself
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