Hi,
Can anyone please solve these 4 questions from GMAT PREP test-1 for me please ?
just realized that 2 of the 4 questions in the attachment are from Data Sufficiency but would still appreciate if anyone can solve them for me.. thanks once again
Thanks
CB
GMAT PREP-1 Questions.. help needed
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Answer to 2)
Initial Height = 4ft
Let the constant amount be X.
After 1 year : 4+x
After 2 years : (4+x) + x = 4+2x
After 3 years : (4+2x) + x = 4+3x
.
.
.
After 6 years : 4+6x
Given,
4+6x= 4+4x + 1/5(4+4x)
Solving,X = 2/3
You must have made the mistake of writing,
4+6x=1/5(4+4x) which is wrong.
Problem 3)
Mixture 1 : 10% gravel and quantity : x tonnes
Therefore amount of gravel : 0.1x
Mixture 2 : 2% gravel,and y tonnes
Amount of gravel : 0.02y
They are mixed to produce a mixture of z tonnes that is 5% gravel
Hence, 0.1x+0.02y=0.05z
We need x.
Statement 1
-----------
y=10
Now x+y=z
x+10=z
Putting it in the equation
0.1x+10*0.02=(x+10)0.05
We can get x,hece sufficient.
Statement 2
-----------
z=16
==>x+y=16
And we have
0.1x+0.02y=0.05z
i.e
0.1x+0.02y=0.05*16
We can slve for x and y,hence sufficient,
Hence OA-D
Questions 1 and 4,i'll get back if I find the solution.Stuck myself.
Initial Height = 4ft
Let the constant amount be X.
After 1 year : 4+x
After 2 years : (4+x) + x = 4+2x
After 3 years : (4+2x) + x = 4+3x
.
.
.
After 6 years : 4+6x
Given,
4+6x= 4+4x + 1/5(4+4x)
Solving,X = 2/3
You must have made the mistake of writing,
4+6x=1/5(4+4x) which is wrong.
Problem 3)
Mixture 1 : 10% gravel and quantity : x tonnes
Therefore amount of gravel : 0.1x
Mixture 2 : 2% gravel,and y tonnes
Amount of gravel : 0.02y
They are mixed to produce a mixture of z tonnes that is 5% gravel
Hence, 0.1x+0.02y=0.05z
We need x.
Statement 1
-----------
y=10
Now x+y=z
x+10=z
Putting it in the equation
0.1x+10*0.02=(x+10)0.05
We can get x,hece sufficient.
Statement 2
-----------
z=16
==>x+y=16
And we have
0.1x+0.02y=0.05z
i.e
0.1x+0.02y=0.05*16
We can slve for x and y,hence sufficient,
Hence OA-D
Questions 1 and 4,i'll get back if I find the solution.Stuck myself.
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- Master | Next Rank: 500 Posts
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The 4th Question is a typo error. Was going through some previous posts and Stuart Kovinsky has pointed out it has to be
2^((x+y)^2)
-----------
2^((x-y)^2)
Then we use
(a^m)/(a^n) = a^(m-n) and then the expression will reduce to 2^4 = 16.
2^((x+y)^2)
-----------
2^((x-y)^2)
Then we use
(a^m)/(a^n) = a^(m-n) and then the expression will reduce to 2^4 = 16.