Can someone please give a quick explanation? Thanks.
1)
Month Average Price/Dozen
April $1.26
May $1.20
June $1.08
The table above shows the average (arithm mean) price per dozen of the large grade A eggs sold in a store during three successive months. If 2/3 as many dozen were sold in April as in May, and twice as many were sold in June, what was the average price per dozen of the eggs sold over the three-month period?
(A) $1.08
(B) $1.10
(C) $1.14
(D) $1.16
(E) $1.18
2)
If y does not equal 3 and (3x)/y is a prime integer greater than 2, which of the following must be true?
I. x = y
II. y = 1
III. x and y are prime integers
(A) None
(B) I only
(C) II only
(D) III only
(E) I and III
Official answers are D and A, respectively.
prep questions
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- jayhawk2001
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Let x be the number of dozen eggs sold in maybww wrote:Can someone please give a quick explanation? Thanks.
1)
Month Average Price/Dozen
April $1.26
May $1.20
June $1.08
The table above shows the average (arithm mean) price per dozen of the large grade A eggs sold in a store during three successive months. If 2/3 as many dozen were sold in April as in May, and twice as many were sold in June, what was the average price per dozen of the eggs sold over the three-month period?
Avg price = total sale price / total eggs sold
= (2/3*x*1.26 + x*1.2 + 2*x*1.08 ) / (2/3x + x + 2x)
= 4.2*x / (11/3*x)
= 1.145
I'm not getting D
3x/y is prime.bww wrote: 2)
If y does not equal 3 and (3x)/y is a prime integer greater than 2, which of the following must be true?
I. x = y
II. y = 1
III. x and y are prime integers
(A) None
(B) I only
(C) II only
(D) III only
(E) I and III
Official answers are D and A, respectively.
Take x = 1 and y = 3/7.
I, II and III don't hold true for the above but 3x/y = 7 > 2 and is prime
Hence A
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Let 6 dozens be sold in May...So 2/3*6 = 4 will be sold in April and 12 will be sold in June
So average = (1.26*4)+(1.20*6)+(12*1.08 ) / 22
= 25.20/22 = 1.14 (Approx)
So average = (1.26*4)+(1.20*6)+(12*1.08 ) / 22
= 25.20/22 = 1.14 (Approx)
Last edited by Cybermusings on Tue May 08, 2007 2:56 am, edited 1 time in total.
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Statement II : Can't be true...If y = 1 and x = 1 then 3x/y becomes a prime integer greater than 2. However, if y = 1 and x = 4, then 3x/y = 3*4 = 12/1 which is not prime
Statement I : Has to be always true ; otherwise 3x/y will not be a prime integer. try substituting any value where x is not equal to y. Hence x = y
Statement III : If x = y then x = y = 1,2,4,5,6 anything; and still 3x/y will be a prime integer greater than 2. Hence III is not true always
So answer is I only
Statement I : Has to be always true ; otherwise 3x/y will not be a prime integer. try substituting any value where x is not equal to y. Hence x = y
Statement III : If x = y then x = y = 1,2,4,5,6 anything; and still 3x/y will be a prime integer greater than 2. Hence III is not true always
So answer is I only
- jayhawk2001
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For I, how about x = 1 and y = 3/7. Since we aren't given that x and y areCybermusings wrote:Statement II : Can't be true...If y = 1 and x = 1 then 3x/y becomes a prime integer greater than 2. However, if y = 1 and x = 4, then 3x/y = 3*4 = 12/1 which is not prime
Statement I : Has to be always true ; otherwise 3x/y will not be a prime integer. try substituting any value where x is not equal to y. Hence x = y
Statement III : If x = y then x = y = 1,2,4,5,6 anything; and still 3x/y will be a prime integer greater than 2. Hence III is not true always
So answer is I only
integers, I'm not sure if we can make the assumption (i.e. x=y)
Please correct if I have it interpreted it wrongly.
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I have posted the same question and someone answered it, here is the solution
Given:
Aa,Am,Aj=(1.26,1.20,1.080 )
Sa=Sm
Sj=2Sa
Total Sales=Sa+Sm+Sj
=Sa+Sa+2Sa
=4Sa
3-Month Avg=Sales Price*Sale/Total Sales
=(Sa*Aa + Sm * Am + Sj * Aj) / ( Sa + Sm + Sj)
= (Sa * Aa + Sa * Am + 2Sa * Aj ) / 4Sa
=Sa (Aa+Am+2Aj)/4 (Sa)
= (Aa+Am+2Aj)/4
=(1.26+1.20+2*1.080)/4
=1.155
~=1.16 = D
Given:
Aa,Am,Aj=(1.26,1.20,1.080 )
Sa=Sm
Sj=2Sa
Total Sales=Sa+Sm+Sj
=Sa+Sa+2Sa
=4Sa
3-Month Avg=Sales Price*Sale/Total Sales
=(Sa*Aa + Sm * Am + Sj * Aj) / ( Sa + Sm + Sj)
= (Sa * Aa + Sa * Am + 2Sa * Aj ) / 4Sa
=Sa (Aa+Am+2Aj)/4 (Sa)
= (Aa+Am+2Aj)/4
=(1.26+1.20+2*1.080)/4
=1.155
~=1.16 = D
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Good questions...
I believe they are from
https://gmat1000ps.blocked
SECTION 1
Question number 19 and 20
I believe they are from
https://gmat1000ps.blocked
SECTION 1
Question number 19 and 20
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Let us consider
April $1.26 No of Eggs = 4
May $1.20 6
June $1.08 2
Therefore total no of eggs = 4+6+2=12
Total Price 1.26*4+1.20*6+1.08*2=5.04+7.2+2.16=14.4
Average = 14.4/12=1.2
April $1.26 No of Eggs = 4
May $1.20 6
June $1.08 2
Therefore total no of eggs = 4+6+2=12
Total Price 1.26*4+1.20*6+1.08*2=5.04+7.2+2.16=14.4
Average = 14.4/12=1.2
- arora007
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The number of eggs in June is incorrect. try solving again...gupta.ansh13 wrote:Let us consider
April $1.26 No of Eggs = 4
May $1.20 6
June $1.08 2
Therefore total no of eggs = 4+6+2=12
Total Price 1.26*4+1.20*6+1.08*2=5.04+7.2+2.16=14.4
Average = 14.4/12=1.2
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