Mixtures and Ratios

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Mixtures and Ratios

by warlock » Mon Jul 28, 2008 2:32 am
Three quarts of a bleaching chemical, Minum, contains 5 percent hydrogen peroxide and water. A different type of bleaching chemical, Maxim, which contains 20 percent hydrogen peroxide, will be mixed with the three quarts of Minum. How much of type Maxim should be added to the three quarts of Minum so that the resulting mixture contains 15 percent hydrogen peroxide?

A. 3 quarts
B. 3.75 quarts
C. 4.5 quarts
D. 6 quarts
E. 9 quarts

Can anyone explain me the procedure. thank you.

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by sudhir3127 » Mon Jul 28, 2008 2:41 am
My Answer is 6

Here it goes...

3 qts Minum contains 5% hydrogen peroxide = 3*5/100 = 0.15 quarts
Water = 3-0.15 = 2.85 quarts

Let the quantity of Maxim be X,
x qts of maxim contains 20 percent hydrogen peroxide
= X* 20/100= 0.2X
Water = X - 0.2X= 0.8X

Total Mixture = 3+X
hydrogen peroxide = 0.2X+ 0.15

in the mixture hydrogen peroxide is 15% of the total amount

(0.20x+0.15) = 15*(3+x)/100
20x + 15 = 45 + 15x
5x = 30
x=6

Please let me know if have doubts ...

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by ricky » Mon Jul 28, 2008 3:16 am
Answer is D mate

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by parallel_chase » Mon Jul 28, 2008 3:34 am
original Qty=3
Hydrogen = 5% of 3

added Qty=x
hydrogen=20%x

new formed Qty=x+3
hydrogen=15%(x+3)

equation:

5%of3+20%x = 15%(x+3)

solve for x

X=6

Hence D

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by evansbd » Mon Jul 28, 2008 6:01 am
I think a good way to look at this problem is the following.

part/whole = percentage (everyone knows this)

We can see that Maxim will be our variable.


PART
3 Quarts Minum + Maxim

3(.005) + 0.20X

Whole
How many quarts of Maxim added to 3 quarts Minum

X + 3


part/whole = .15

3(.005) + 0.20X
______________ = .15

X + 3


Solving for X as everyone else did you will get 6 but I think its easier to see if you can look at it as a simple percentage problem.

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by jsl » Mon Jul 28, 2008 6:14 am
Isn't the answer A (3) because the question asks "How much of type Maxim should be added to the three quarts of Minum"?

6 is the total amount of peroxide isn't it?

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no amigo,

by hakyology » Mon Jul 28, 2008 9:57 am
no, the answer is 6.
so that the total is 9.

this is my formula.

(0.15 + 0.2x )/ (3 + x ) = 0.15

when you solve this, you will get x=6.

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by warlock » Mon Jul 28, 2008 7:25 pm
thank you all...

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by Viren1808 » Wed Nov 02, 2011 9:38 am
Can anyone please help me to solve this question via Aligation method??

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by neelgandham » Wed Nov 02, 2011 9:51 am
Viren1808 wrote:Can anyone please help me to solve this question via Aligation method??
Here it goes !
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by GMATGuruNY » Wed Nov 02, 2011 11:54 am
warlock wrote:Three quarts of a bleaching chemical, Minum, contains 5 percent hydrogen peroxide and water. A different type of bleaching chemical, Maxim, which contains 20 percent hydrogen peroxide, will be mixed with the three quarts of Minum. How much of type Maxim should be added to the three quarts of Minum so that the resulting mixture contains 15 percent hydrogen peroxide?

A. 3 quarts
B. 3.75 quarts
C. 4.5 quarts
D. 6 quarts
E. 9 quarts

Can anyone explain me the procedure. thank you.
Another approach would be to plug in the answers.

Since the percentage in the mixture (15%) is closer to the percentage in Maxim (20%), the mixture must be more than 1/2 Maxim.
Eliminate A.
Of the remaining answer choices, we should start with the next greatest that is an integer.

Amount of hydrogen peroxide in Minum = .05(3) = .15.

Answer choice D: 6 quarts Maxim.
Amount of hydrogen peroxide in Maxim = .2(6) = 1.2 .
Total hydrogen peroxide/Total mixture = (.15+1.2)/(3+6) = 1.35/9 = 135/900 = 15/100 = 15%.
Success!

The correct answer is D.
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by Scott@TargetTestPrep » Tue Jan 09, 2018 10:08 am
warlock wrote:Three quarts of a bleaching chemical, Minum, contains 5 percent hydrogen peroxide and water. A different type of bleaching chemical, Maxim, which contains 20 percent hydrogen peroxide, will be mixed with the three quarts of Minum. How much of type Maxim should be added to the three quarts of Minum so that the resulting mixture contains 15 percent hydrogen peroxide?

A. 3 quarts
B. 3.75 quarts
C. 4.5 quarts
D. 6 quarts
E. 9 quarts
We can let the number of quarts of Maxim = y and create the following equations:

0.05(3) + 0.2y = 0.15(3 + y)

5(3) + 20y = 15(3 + y)

15 + 20y = 45 + 15y

5y = 30

y = 6

Answer: D

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