Data Sufficiency

Guys,

For the DS Qn #62, try it and let me know how long its taking you to get an answer.

My first attempt took me 2:45 to answer the question and my second attempt took me 3:10 to answer the question. Is this question supposed to be a question I need to know how to do in under 2 minutes?

How do I know if I'm realistically supposed to answer a question in under 2 minutes or not without constantly posting my question (like this one) here?

Can you post this question please ?

Moved to Data Sufficiency folder!

I would, but it's in the OG book. Why not try it?

The problem is that I'm at work and it'd be wrong if I just took out my book right now in front of my colleagues!

Sure, I'll post it and the question should only take 30seconds tops to solve, I'll go over my solution and reasoning.
OA: D


Let x be dollars (as stated in the question).

Statement 1:

120 + x(4 - 1) = 45 --> That's all you need, you isolated 1 variable. No need to solve any further. Suff.

Statement 2:

120 + x(2 - 1) = 120 + x(4 - 1) + 45 --> Same deal, you isolated x. No need to solve any further. Suff.

student22 wrote:Sure, I'll post it and the question should only take 30seconds tops to solve, I'll go over my solution and reasoning.

Code: Select all

For a convention, a hotel charges a daily room rate of $120 for 1 person and x dollars for each additional person. What is the charge for each additional person?

(1) The daily cost per person for 4 people sharing the cost of a room equally is $45.
(2) The daily cost per person for 2 people sharing the cost of a room equally is $25 more than the corresponding cost for 4 people.

OA: D


Let x be dollars (as stated in the question).

Statement 1:

120 + x(4 - 1) = 45 --> That's all you need, you isolated 1 variable. No need to solve any further. Suff.

Statement 2:

120 + x(2 - 1) = 120 + x(4 - 1) + 45 --> Same deal, you isolated x. No need to solve any further. Suff.

I amnot sure if i can finish in 30 secs.I took more than a minute...(but correct soln)
The step above mentioned by the other user is NOT correct.

st 1:120 + 3x =45(4) = 180.
st 2:(120 + x )/2= ((120 +3x)/4) +25

solving any of the equations u shuld get X=20$.

SO D....

After all GMAT cant ask our IIT maths...so GMAC need to be contended with tough English that really make us(atleast me) scary..Uffffffffffffffffffffff

Good catch, I solved it too quickly and missed the part of per person. So yes you have to multiply by 4 in the first one and divide each one by 2 and 4 respectively on the second statement.

But my original point still stands, the question gives you three variables. X for dollars for additional persons AND let's say N for the number of additional persons AND the total cost T of the room.

What you should be looking for in each statement is an answer to 2 of those questions. Statement 1 gives you an answer to the total cost 45 * 4 and the number of people N which is 4. So you intuitively know without even writing an equation that you only have one variable left, X.

The second statement gives you N by giving you 2 and 4 people. And it answers the question of total cost by telling you the relative price, that the cost for 2 people is equal to + 25 for the cost of 4 people. This tells you that you only have X left to solve. Again, no need to even write an equation.

piyushdabomb wrote:Guys,

For the DS Qn #62, try it and let me know how long its taking you to get an answer.

My first attempt took me 2:45 to answer the question and my second attempt took me 3:10 to answer the question. Is this question supposed to be a question I need to know how to do in under 2 minutes?

How do I know if I'm realistically supposed to answer a question in under 2 minutes or not without constantly posting my question (like this one) here?

Answer : D

Took me around 30 secs to do this. May be because I have done this problem earlier.
But in any case I dont think it should take more than 1 minute to complete. This would probably be categorized as a 600-700 level problem.