If it is 6:27 in the evening on a certain day, what time in

Convert the 2,880,717 minutes to hours by dividing by 60.

=> 2,880,717 / 60 = 48,011 (hours) and remainder of 57 (minutes)

Since time is 6:27 and you subtract 57 minutes => 6:30. Thus, D is the correct solution.

Hi stanford2012

What is the meaning of :

Since time is 6:27 and you subtract 57 minutes => 6:30

Regards,
Subhash

@ subhashgosh

All the answer choices are in the following format: 6:XX where 6 represents the hour and XX represents the minutes.

As a result you only have to care about how many minutes you have to subtract from 6:27. Given that 2,880,717 / 60 = 48,011 (hours) and remainder of 57 (minutes) you should simply subtract 57 from 6:27, which yields 5:30. Since there are only hours left to subtract the minutes won't change anymore. Thus, D (6:30) is the correct solution.

Hope it"s clear.

Looked at the units place

7-7= 0

Answer = D = 6:30

Hard to think this is an "easy" question...took me about a good 4-5min to solve but....


take 2,880,717 and before you divide it by 60, take all the combination of numbers that are divisible by 6
the largest being 2,880 since (8+8+2=18) which is 6x3

Then i thought 717 which actually is divisible by 3 (239x3) was prime but said...if 60x24= 1440 then 1440/2=12hrs=720

720-717=3min

6:27 + 3mins = 6:30

Surprised I didn't choose B

I really don't think this question was meant to be 'solved' in the traditional manner by breaking it up into minutes etc., though all the approaches above that have done that have been analytically correct. Each one of these approaches is valid, and would in fact have been needed if there had been more than one option ending with a 0. However, that is not the case here and we must try and look for a quicker method. The GMAT does not usually require test-takers to enter into laborious calculations, so we must look for some other way to solve this.

As pointed out by Bunuel and PareshGmat, one must look at the last digit. If it is 6:27 now, what time would it have been 7 minutes earlier? 6:20 (notice the 0 at the end). How about 27 minutes earlier? Again, a 0 at the end. 277? 222777? Again, no matter what, will end with a 0. Therefore, looking at the options, we can quickly conclude that this would end with a 0 and then choose D.

Option D
2880000 min=2000 days.
The leftover 717 minutes=11 hrs 57 min
Ans 6:27-11hrs 57min=6:30 morning

Apart from concept of 0,I did not understand why B is not answer.

All of the other minutes will pass away. Let's just focus on last 3 digits and check what is the remainder when divided by 60.
717. Closest multiples 600 then 720. So that means at 714 minutes it will exactly be the same time. Now 715 will be 6:28. 716 will be 6:29. 717 will be 6:30.

(1st) Convert the Minutes into Hours

2,880,717 min * (1 hr / 60 min) = H hours

48, 011 hours with (57/60) left over -----> which is an extra 57 minutes


(2nd) Remove the 57 minutes

6:27 PM -----> 57 minutes early = 5:30 PM


(3rd) From 5:30 PM, we need to go ----> 48, 011 Hours Back

48,000 is Divisible by 24 hours. Thus, for the first 48,000 hours, we are just rewinding Day by Day by Day.....

until it is 5:30 PM and we still have 11 Hours remaining to go back by

5:30 PM - 11 hours = 6:30 AM

-D-

2880720 divided by 60 gives reminder "0"
(2880720) - (2880717) difference is 3 min, which needs to be added to 6:27 + 0.03 = 6:30
Option D is the correct option.

A day includes 24 hours which has a total of 1440 minutes.

The number 2880717 can be rewritten as 2800717

=\( 2880000\ +\ 717\)
Dividing the two elements separately with 1440 the remainder is :

717. Since 2880000 is a multiple of 1440.
SInce days repeat in cycles of 1400 minutes.
This is equivalent to 717 minutes earlier

Since we need to consider the minutes earlier from the given time this becomes :
A difference of 720 minutes is equivalent to 6: 27 in the morning and since 717 is 3 minutes closer in comparison :
The time is 6: 27 + 0:03 = 6: 30 am.


Let's make a few observations....

If it is presently 6:27 pm, then:
7 minutes ago, it was 6:20 pm
17 minutes ago, it was 6:10 pm
47 minutes ago, it was 5:40 pm
87 minutes ago, it was 5:00 pm
117 minutes ago, it was 4:30 pm

So........
2,880,717 minutes ago, the time was ?:?0

Check the answer choices to see that only choice D has 0 in the minutes position

This is a problem related to multiples and remainder, we know that every 12 hrs after or before 6:27 would be the exact time, so let's check how many such complete 12 hrs are there

If we divide 2880717 by 12 we will notice that it is 3mins short of being a perfect 12 multiples (i.e 12 hours multiples), and the multiple is 48012

Let X was the time in clock 2880717mins earlier then :
X + (12*48012 hrs - 3 mins) = 6:27
X = 6:27 - 12*48012 hrs + 3 mins = 6:27 + 3 mins ( since some 12 hr multiple added to 6:27 will be 6:27 )

Note: The mistake I was tempted to make is unconsciously substract 3 mins ( carelessly trying to find a time 2880717minutes after 6:27 )

2880717/60 --> 117 left which will leave the remainder 57 or we can see that +3 will make it divisible so 6:27 + 03 = 6:30 hence D is the answer.