Word Peoblem -DS

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Word Peoblem -DS

by kop » Wed Nov 20, 2013 2:41 am
A painter wishes to paint a house turquoise. To make the color, he selects an eggshell primer made up of 70% pure-white color, and combines it with a blue base coat in order to create a turquoise color made up of 75% pure-white. How many quarts from the blue base coat should be mixed to make enough turquoise to paint the house?

1. It will take 300 quarts of paint to cover the house.
2. The blue base-coat is made up of 90% pure-white color.
Source: — Data Sufficiency |

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by pareekbharat86 » Wed Nov 20, 2013 4:30 am
Suppose the no. of quarts of egg-shell primer= x
Suppose the no. of quarts of blue base primer= y

Total white colour obtained from egg-shell primer = 70%*x

What we require is value of Y.

We can write this equation down to help us get the desired variables

X*70% + Y*(?? %)= (x+y)* 75%

Statement-1
x+y= 300

Therefore our eqn. becomes X*70% + Y*(?? %)= 300* 75%
But we still have 3 unknowns. Therefore, INSUFFICIENT

Statement-2
Blue base-coat is made up of 90% pure-white colour

Therefore our eqn. becomes X*70% + Y*90%= (x+y)* 75%
We can't really move further. INSUFFICIENT.

Combining 1 & 2, our equation becomes,

X*70% + Y*90%= 300 * 75%= 225

We have x+y=300

Equating both we get X= 225 and Y = 75.

SUFFICIENT.

Answer C?
Thanks,
Bharat.

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by theCodeToGMAT » Wed Nov 20, 2013 5:23 am
M2 = 70% pure-white color
M1 = % of Blue base
M = 75% pure-white
N1= pure-white
N2= Blue base

To find: Value of N2

Using Weighted Average:
N1/N2=(M2-M)/(M-M1)

Statement 1:
N1 + N2 = 300
we have no relation between N1 & N2
INSUFFICIENT

Statement 2:
N2 = (0.90) N1
We don't have total of N1 & N2.
INSUFFICIENT

Combining...
N1 + N2 = 300
N2 = (0.90) N1
We can solve to get N1 and N2..
SUFFICIENT

Answer [spoiler]{C}[/spoiler]
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