If Juan had a doctor's appointment on a certain day, was the

This is a data sufficiency question. Options for DS questions are always the same.

The data sufficiency problem consists of a question and two statements, labeled (1) and (2), in which certain data are given. You have to decide whether the data given in the statements are sufficient for answering the question. Using the data given in the statements, plus your knowledge of mathematics and everyday facts (such as the number of days in July or the meaning of the word counterclockwise), you must indicate whether—

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient to answer the question asked.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient to answer the question asked.
C. BOTH statements (1) and (2) TOGETHER are sufficient to answer the question asked, but NEITHER statement ALONE is sufficient to answer the question asked.
D. EACH statement ALONE is sufficient to answer the question asked.
E. Statements (1) and (2) TOGETHER are NOT sufficient to answer the question asked, and additional data specific to the problem are needed.

I suggest you to go through the following post ALL YOU NEED FOR QUANT.

Hope this helps.

Hi Bunuel,

Have a specific question with the solution.

The question stem specifically ask whether the day is Wednesday. Statement 1 mentioned that exactly 60 hours before the appointment was Monday. Hence for this particular statement don't you think one should calculate in reverse order.

If the appointment was on 9.00 pm of Wednesday, 60 hours before this time will be for sure Monday. But if the appointment on 9.00 am of Wednesday, 60 hours before this time will be for sure Sunday. However, the later part is out of scope, because statement 1 is mentions that exactly 60 hours before the appointment was Monday.

Where is my reasoning incorrect?

Thanks in advance.

Amrish

Hello amrishsoni86.

If you start calculating in reverse order this is actually change nothing.
As you wrote: if appointment was on Wednesday at 9:00 am when this is contradict to information in statement 1 that 60 hours before was Monday and we can infer that appointment can't be at 9:00 am at Wednesday.

So it doesn't matter what you take as a start point extreme time points at Wednesday or extreme time points at Monday
First case (extreme points Wednesday)
13:00 Wednesday - 1 statement is true (-60 hours = 1:00 Monday) and appointment was on Wednesday
1:00 Thursday - 1 statement is true (-60 hours = 13:00 Monday) but appointment was in Thursday

Second case (extreme points Monday)
1:00 Monday - 1 statement true and appointment was on Wednesday 13:00
13:00 Monday - 1 statement true and appointment was on Thursday 1:00

Does that make sense?

IMO, you are correct that per statement 1 , the process should be looked at in reverse. For any particular day, the 24 hours start from 0000 hours to 2359 hours. So per statement 1, 60 hours before the appointment was a monday. Now lets think it this way:

For the actual appointment to be on wednesday, think of it this way:

60 hours before 2359 on Wednesday : 1159 (or 1159 AM on Monday) but 60 hours from 0000 Wednesday fall on 1200 on Sunday. Thus , this statement is not sufficient and additionally, for the appointment to be on wednesday and 60 hours being Monday , the only scenario is for the appointment to be between 1201 and 2359 hours on wednesday.

From my experience, one of the 2 statements (sometimes) throws us a hint or two about some of the cases we might have missed. For this question. statement 2 gave me the hint to think about the period from 1 pm to 9 pm in particular (though this method might not be applicable to all the questions and lead to unnecessary time wastage!).

Hope this is clear.

Fully agree "Harley1980". In face I was thinking about this question after I posted on the forum and realized that I missed the Thursday part. But your explanation is clarifying the confusion perfect. Thanks again for the effort. All the best. Armish

Agree Engr2012. However, after heavily solving statement 1 when one read statement 2, one start using the information together and do not realize that statement 2 alone could have answered . May be a trap that I always fall to, I have to overcome this.

Anyway, thanks for your effort to explain. All the best. Amrish

each statement alone is insufficient...By considering two statement
it can be concluded that the appoint is wednesday. and 60 hours before the appointment was monday.

This is how I solved.

Calculate in reverse.
Statement 1

: Exactly 60 hours before the appointment, it was Monday.

So lets say the 60th hour was 2300 hours on Monday and add 59 hours to it you will notice
1 hour on mon + 24 hours on tues + 24 hours on wed + 11 hours on thurday will be the appointment

But if you calculate from 1 am on Monday then we have 23 hours on Monday + 24 on Tuesday + 13 on Wednesday : So it could be Wed too .

since no clear ans rule out option 1

Option 2 (2) The appointment was between 1:00 pm and 9:00 pm does not give any information to conclude meeting was on Wednesday

So Option a , b and D ruled out

Together we know appointment was between 1 and 9 pm and 60 hours before meeting was Monday.

TEst answers with both options eg : if meeting was 9 pm on Wednesday will it still be Monday ie 60 hours before ; ans is yes
If meeting was at 1 pm it will still be Monday so together sufficient . Ans = C

Y/N Question: If Juan had a doctor's appointment on a certain day, was the appointment on a Wednesday?

(1) Exactly 60 hours before the appointment, it was Monday.
We want to min/max the starting time to see where the appointment can fall

MIN: 23:59 PM Mon -> 23:59 PM Tue -> 23:59 PM Wed -> 11:59 AM Thu
- - - - - - 0:01 - - - - - - - - 24:01 - - - - - - - 48:01 - - - - - - - 60:00
MAX: 00:00 AM Mon -> 00:00 AM Tue -> 12:00 PM Wed
- - - - - - 24:00 - - - - - - - - 48:00 - - - - - - - 60:00

So the appointment could be on Wed or Thursday, not sufficient.

(2) The appointment was between 1:00 pm and 9:00 pm
No info about the day it is on, not sufficient.

(1&2) Looking at the chart in (1) we can see that in order for it to be between 1:00 and 9:00 PM it would have to be on Wednesday since the latest possible time is 11:59 AM on Thursday. Definite YES, Sufficient.

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