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The cost of delivery for an order of desk chairs was $10.00

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The cost of delivery for an order of desk chairs was $10.00 for the first chair, and $1.00 for each additional chair in the order. If an office manager placed an order for n desk chairs, is n > 24 ?

(1) The delivery cost for the order totalled more than $30.00.
(2) The average (arithmetic mean) delivery cost of the n chairs was $1.36.
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Simple one.

Using (1), the total is to be more than $30, which can be the case if n is greater than or less than 24. For instance, when n=22, the total cost is $31, but when n=25, the total cost is $34, which are both greater than $30. Insufficient.
Using (2), we are given that [10 + (n-1)]/n = 1.36
=> n= 25, which is greater than 24. Sufficient.

The answer is (B).
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(1) only tells us n >= 21; not sufficient by itself
(2) tells us [10+n-1]/n = 1.36; which will lead to a definitive answer and therefore is sufficient by itself

Thus, B.

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Re: The cost of delivery for an order of desk chairs was $10.00 [#permalink]

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The cost of delivery for an order of desk chairs was $10.00 for the first chair, and $1.00 for each additional chair in the order. If an office manager placed an order for n desk chairs, is n > 24 ?

According to the rule given in the stem the cost of delivery for n chairs is $10+$1*(n-1)=9+n.

(1) The delivery cost for the order totalled more than $30.00 --> 9+n>30 --> n>21, so n may or may not be more than 24. not sufficient.

(2) The average (arithmetic mean) delivery cost of the n chairs was $1.36 --> (average cost)=(total cost)/(# of chairs)=(9+n)/n. We are told that (9+n)/n=1.36 --> we can find the exact numerical value of n. Sufficient.

Answer: B.
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Re: The cost of delivery for an order of desk chairs was $10.00 [#permalink]

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Vote for B

$10 - first chair
$1 - additional

order n

is n>24? i.e. cost should be least 10(1) + 1(23) = $33 for 24 chairs

(A) delivery cost > 30

data not sufficient

(B)

S=An
10+(n-1) = 1.36n
9 + n= 1.36n
9 = 0.36n
9/.36 = n
25 = n

Sufficient

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Re: The cost of delivery for an order of desk chairs was $10.00 [#permalink]

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New post 16 Apr 2012, 00:48
Bunuel wrote:
The cost of delivery for an order of desk chairs was $10.00 for the first chair, and $1.00 for each additional chair in the order. If an office manager placed an order for n desk chairs, is n > 24 ?

According to the rule given in the stem the cost of delivery for n chairs is $10+$1*(n-1)=9+n.

(1) The delivery cost for the order totalled more than $30.00 --> 9+n>30 --> n>21, so n may or may not be more than 24. not sufficient.

(2) The average (arithmetic mean) delivery cost of the n chairs was $1.36 --> (average cost)=(total cost)/(# of chairs)=(9+n)/n. We are told that (9+n)/n=1.36 --> we can find the exact numerical value of n. Sufficient.

Answer: B.


awesome as you have rephrased the statement,.

We could think also in this way: 1 chair cost 10 and the others 1 more $. for 24 chairs we have a total of 33 $. so we could say: is total cost more than 33$ ??? is correct bunuel ??

also is unclear :( (n-1) in the formula above is not : Tot= 10 + 1*N ??????? N is the number of chair.....

thanks Moderator.
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Re: The cost of delivery for an order of desk chairs was $10.00 [#permalink]

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carcass wrote:
Bunuel wrote:
The cost of delivery for an order of desk chairs was $10.00 for the first chair, and $1.00 for each additional chair in the order. If an office manager placed an order for n desk chairs, is n > 24 ?

According to the rule given in the stem the cost of delivery for n chairs is $10+$1*(n-1)=9+n.

(1) The delivery cost for the order totalled more than $30.00 --> 9+n>30 --> n>21, so n may or may not be more than 24. not sufficient.

(2) The average (arithmetic mean) delivery cost of the n chairs was $1.36 --> (average cost)=(total cost)/(# of chairs)=(9+n)/n. We are told that (9+n)/n=1.36 --> we can find the exact numerical value of n. Sufficient.

Answer: B.


awesome as you have rephrased the statement,.

We could think also in this way: 1 chair cost 10 and the others 1 more $. for 24 chairs we have a total of 33 $. so we could say: is total cost more than 33$ ??? is correct bunuel ??

also is unclear :( (n-1) in the formula above is not : Tot= 10 + 1*N ??????? N is the number of chair.....

thanks Moderator.


The cost of the first chair is $10 and $1 for each additional chair.

So, for n chairs one chair goes for $10 and the rest n-1 chairs go for $1 each, total $10+$1*(n-1)=9+n.

Hope it's clear.
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Re: The cost of delivery for an order of desk chairs was $10.00 [#permalink]

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New post 04 Aug 2013, 06:18
Bunuel wrote:
The cost of delivery for an order of desk chairs was $10.00 for the first chair, and $1.00 for each additional chair in the order. If an office manager placed an order for n desk chairs, is n > 24 ?

According to the rule given in the stem the cost of delivery for n chairs is $10+$1*(n-1)=9+n.

(1) The delivery cost for the order totalled more than $30.00 --> 9+n>30 --> n>21, so n may or may not be more than 24. not sufficient.

(2) The average (arithmetic mean) delivery cost of the n chairs was $1.36 --> (average cost)=(total cost)/(# of chairs)=(9+n)/n. We are told that (9+n)/n=1.36 --> we can find the exact numerical value of n. Sufficient.

Answer: B.



I am not so good at translating words to numbers, could you post some similar problems to practice the skill?
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Re: The cost of delivery for an order of desk chairs was $10.00 [#permalink]

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Stiv wrote:
Bunuel wrote:
The cost of delivery for an order of desk chairs was $10.00 for the first chair, and $1.00 for each additional chair in the order. If an office manager placed an order for n desk chairs, is n > 24 ?

According to the rule given in the stem the cost of delivery for n chairs is $10+$1*(n-1)=9+n.

(1) The delivery cost for the order totalled more than $30.00 --> 9+n>30 --> n>21, so n may or may not be more than 24. not sufficient.

(2) The average (arithmetic mean) delivery cost of the n chairs was $1.36 --> (average cost)=(total cost)/(# of chairs)=(9+n)/n. We are told that (9+n)/n=1.36 --> we can find the exact numerical value of n. Sufficient.

Answer: B.



I am not so good at translating words to numbers, could you post some similar problems to practice the skill?


search.php?search_id=tag&tag_id=183 for DS
search.php?search_id=tag&tag_id=56 for PS

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New post 11 Dec 2013, 18:01
Vidhi1 wrote:
The cost of delivery for an order of desk chairs was $10.00 for the first chair and $1.00 for each additional chair in the order. If an office manager placed an order for n desk chairs, is n>24?

1. The delivery cost for the order totaled more than $30.00
2. The average (arithmetic mean) delivery cost of the n chairs was $1.36


So, now we can see that, for statement 1, the question is how much more than $30.00? At $31.00, n<24, while at, say $300.00, n>24.

For statement 2, from the average and the information in the stem, we can calculate n: (10 + (n-1))/n = 1.36, so n = 25.

So, the correct response is B.
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Re: The cost of delivery for an order of desk chairs was $10.00 [#permalink]

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New post 21 Jul 2014, 03:17
Bunuel wrote:
carcass wrote:
Bunuel wrote:
The cost of delivery for an order of desk chairs was $10.00 for the first chair, and $1.00 for each additional chair in the order. If an office manager placed an order for n desk chairs, is n > 24 ?

According to the rule given in the stem the cost of delivery for n chairs is $10+$1*(n-1)=9+n.

(1) The delivery cost for the order totalled more than $30.00 --> 9+n>30 --> n>21, so n may or may not be more than 24. not sufficient.

(2) The average (arithmetic mean) delivery cost of the n chairs was $1.36 --> (average cost)=(total cost)/(# of chairs)=(9+n)/n. We are told that (9+n)/n=1.36 --> we can find the exact numerical value of n. Sufficient.

Answer: B.


awesome as you have rephrased the statement,.

We could think also in this way: 1 chair cost 10 and the others 1 more $. for 24 chairs we have a total of 33 $. so we could say: is total cost more than 33$ ??? is correct bunuel ??

also is unclear :( (n-1) in the formula above is not : Tot= 10 + 1*N ??????? N is the number of chair.....

thanks Moderator.


The cost of the first chair is $10 and $1 for each additional chair.

So, for n chairs one chair goes for $10 and the rest n-1 chairs go for $1 each, total $10+$1*(n-1)=9+n.

Hope it's clear.

]
worndering where 9+n came from. I was plugging in numbers to find averages - 11, 6, etc...crazy
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Re: The cost of delivery for an order of desk chairs was $10.00 [#permalink]

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New post 21 Jul 2014, 03:23
amenon55 wrote:
Bunuel wrote:
carcass wrote:

awesome as you have rephrased the statement,.

We could think also in this way: 1 chair cost 10 and the others 1 more $. for 24 chairs we have a total of 33 $. so we could say: is total cost more than 33$ ??? is correct bunuel ??

also is unclear :( (n-1) in the formula above is not : Tot= 10 + 1*N ??????? N is the number of chair.....

thanks Moderator.


The cost of the first chair is $10 and $1 for each additional chair.

So, for n chairs one chair goes for $10 and the rest n-1 chairs go for $1 each, total $10+$1*(n-1)=9+n.

Hope it's clear.

]
worndering where 9+n came from. I was plugging in numbers to find averages - 11, 6, etc...crazy


The cost of the first chair is $10 and $1 for each additional chair.

So, for n chairs one chair goes for $10 and the rest n-1 chairs go for $1 each, total $10+$1*(n-1)=9+n.
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The cost of delivery for an order of desk chairs was $10.00 [#permalink]

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New post 21 Jul 2015, 05:48
ruturajp wrote:
The cost of delivery for an order of desk chairs was $10.00 for the first chair, and $1.00 for each additional chair in the order. If an office manager placed an order for n desk chairs, is n > 24 ?

(1) The delivery cost for the order totalled more than $30.00.
(2) The average (arithmetic mean) delivery cost of the n chairs was $1.36.


Given : $10 for first chair and $1 for each additional Chair

i.e. Total Cost of n chairs = 10 + (n-1)*1

Question : Is n > 24 ?

Statement 1: The delivery cost for the order totalled more than $30.00.
10 + (n-1)*1 > 30
i.e. n > 21
NOT SUFFICIENT

Statement 2: The average (arithmetic mean) delivery cost of the n chairs was $1.36.
[10 + (n-1)*1]/n = 1.36
i.e. 1.36n = 10 + (n-1)
i.e. 0.36n = 9
i.e. n = 25
SUFFICIENT

Answer: Option B
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Re: The cost of delivery for an order of desk chairs was $10.00 [#permalink]

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New post 07 Sep 2015, 07:16
Bunuel wrote:
The cost of delivery for an order of desk chairs was $10.00 for the first chair, and $1.00 for each additional chair in the order. If an office manager placed an order for n desk chairs, is n > 24 ?

According to the rule given in the stem the cost of delivery for n chairs is $10+$1*(n-1)=9+n.

(1) The delivery cost for the order totalled more than $30.00 --> 9+n>30 --> n>21, so n may or may not be more than 24. not sufficient.

(2) The average (arithmetic mean) delivery cost of the n chairs was $1.36 --> (average cost)=(total cost)/(# of chairs)=(9+n)/n. We are told that (9+n)/n=1.36 --> we can find the exact numerical value of n. Sufficient.

Answer: B.


Hi Bunuel
If stmnt 2 would be The average (arithmetic mean) delivery cost of the n chairs was greater than $1.36
then we get n<25 --> in that case, number of chairs could be 24,23,1, 10 in any case answer will be NO, n>24? NO hence sufficient
am I right?

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Re: The cost of delivery for an order of desk chairs was $10.00 [#permalink]

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New post 07 Sep 2015, 07:21
anupamadw wrote:
Bunuel wrote:
The cost of delivery for an order of desk chairs was $10.00 for the first chair, and $1.00 for each additional chair in the order. If an office manager placed an order for n desk chairs, is n > 24 ?

According to the rule given in the stem the cost of delivery for n chairs is $10+$1*(n-1)=9+n.

(1) The delivery cost for the order totalled more than $30.00 --> 9+n>30 --> n>21, so n may or may not be more than 24. not sufficient.

(2) The average (arithmetic mean) delivery cost of the n chairs was $1.36 --> (average cost)=(total cost)/(# of chairs)=(9+n)/n. We are told that (9+n)/n=1.36 --> we can find the exact numerical value of n. Sufficient.

Answer: B.


Hi Bunuel
If stmnt 2 would be The average (arithmetic mean) delivery cost of the n chairs was greater than $1.36
then we get n<25 --> in that case, number of chairs could be 24,23,1, 10 in any case answer will be NO, n>24? NO hence sufficient
am I right?


Yes, if it were (9+n)/n>1.36, it still would be sufficient.
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The cost of delivery for an order of desk chairs was $10.00 [#permalink]

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New post 08 Sep 2015, 06:34
Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and equations ensures a solution.



The cost of delivery for an order of desk chairs was $10.00 for the first chair, and $1.00 for each additional chair in the order. If an office manager placed an order for n desk chairs, is n > 24 ?

(1) The delivery cost for the order totalled more than $30.00.
(2) The average (arithmetic mean) delivery cost of the n chairs was $1.36.

From the original condition, using cost:c gives us c=10+(n-1)1=9+n and thus we have 2 variable (c,n) and 1 equation (c=9+n). Since we need to match the number of variables and equations, we need 1 more equation and we have 1 each in 1) and 2). Therefore D is likely the answer.

In case of 1), c>30, 9+n>30, n>21 therefore the condition is not sufficient(if the range of que includes the range of con then the condition is sufficient)
In case of 2), c=1.36n=9+n, 1.36n-n=9, 0.36n=9, n=25>24 the answer is yes. The condition is sufficient and therefore the answer is B
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Re: The cost of delivery for an order of desk chairs was $10.00 [#permalink]

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New post 25 Nov 2017, 06:56
GyanOne wrote:
Simple one.

Using (1), the total is to be more than $30, which can be the case if n is greater than or less than 24. For instance, when n=22, the total cost is $31, but when n=25, the total cost is $34, which are both greater than $30. Insufficient.
Using (2), we are given that [10 + (n-1)]/n = 1.36
=> n= 25, which is greater than 24. Sufficient.

The answer is (B).


Hi

Is this a+(n-1)d?

where d is 1?

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Re: The cost of delivery for an order of desk chairs was $10.00   [#permalink] 25 Nov 2017, 06:56
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