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Intern
Joined: 25 Jan 2016
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14 Apr 2016, 08:03
10
61
00:00

Difficulty:

65% (hard)

Question Stats:

65% (02:32) correct 35% (02:44) wrong based on 985 sessions

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Dara ran on a treadmill that had a readout indicating the time remaining in her exercise session. When the readout indicated 24 min 18 sec, she had completed 10% of her exercise session. The readout indicated which of the following when she had completed 40% of her exercise session?

A. 10 min 48 sec
B. 14 min 52 sec
C. 14 min 58 sec
D. 16 min 6 sec
E. 16 min 12 sec
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05 May 2016, 20:22
19
9
CoffeeCreamSugar wrote:
Dara ran on a treadmill that had a readout indicating the time remaining in her exercise session. When the readout indicated 24 min 18 sec, she had completed 10% of her exercise session. The readout indicated which of the following when she had completed 40% of her exercise session?

A. 10 min 48 sec
B. 14 min 52 sec
C. 14 min 58 sec
D. 16 min 6 sec
E. 16 min 12 sec

Do a more efficient single calculation:

24 min 18 sec is 90% of her exercise time.
When she completes 40% of her exercise session, the readout will indicate 60% of the time.

So we need $$\frac{6}{9} * 24(\frac{18}{60}) = \frac{81}{5} = 16 ( \frac{1}{5}) = 16 (\frac{12}{60}) =$$16 min 12 sec

*Edited a calculation error.
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14 Apr 2016, 08:13
31
13
90% of the exercise should be completed in 24min 18 sec (1458 sec)

When she completes 40% of her exercise timer should show the time remaining for 60% of her exercise.

If 90% requires 1458 sec then 60% requires --> (60 * 1458)/90 = (2/3)*(1458) = 2 * 486 = 972 secs

Required answer = 972/60 = 16 min 12 sec

##### General Discussion
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05 May 2016, 10:01
CoffeeCreamSugar wrote:
Dara ran on a treadmill that had a readout indicating the time remaining in her exercise session. When the readout indicated 24 min 18 sec, she had completed 10% of her exercise session. The readout indicated which of the following when she had completed 40% of her exercise session?

A. 10 min 48 sec
B. 14 min 52 sec
C. 14 min 58 sec
D. 16 min 6 sec
E. 16 min 12 sec

Let's call 24min and 18sec Y.
24min and 18 sec are: 243/10.
Dara completed 10% of her session, so:
243/10 = 9x/10
x=27 min.
27-Y= 2min+42sec
If Dara completed 40% of her session, the she worked for 4*(2min+42sec) so that the rest of her session will be:
27min-10min&48sec = 16 min 12 sec
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05 May 2016, 19:23
1
24.3 minutes/.9=27 minutes=total time of session
(27)(.6)=16.2 minutes=time remaining when session is 40% completed
16.2 minutes=16 min 12 sec
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Joined: 17 Jan 2016
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06 May 2016, 08:03
2
VeritasPrepKarishma wrote:
CoffeeCreamSugar wrote:
Dara ran on a treadmill that had a readout indicating the time remaining in her exercise session. When the readout indicated 24 min 18 sec, she had completed 10% of her exercise session. The readout indicated which of the following when she had completed 40% of her exercise session?

A. 10 min 48 sec
B. 14 min 52 sec
C. 14 min 58 sec
D. 16 min 6 sec
E. 16 min 12 sec

Do a more efficient single calculation:

24 min 18 sec is 90% of her exercise time.
When she completes 40% of her exercise session, the readout will indicate 60% of the time.

So we need $$\frac{6}{9} * 24(\frac{18}{60}) = \frac{161}{10} = 16 ( \frac{1}{10}) = 16 (\frac{6}{60}) =$$16 min 6 sec

I guess you have a little flaw somewhere. OA is indeed E (16min 12sec), just saying
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08 May 2016, 19:46
broilerc wrote:
VeritasPrepKarishma wrote:
CoffeeCreamSugar wrote:
Dara ran on a treadmill that had a readout indicating the time remaining in her exercise session. When the readout indicated 24 min 18 sec, she had completed 10% of her exercise session. The readout indicated which of the following when she had completed 40% of her exercise session?

A. 10 min 48 sec
B. 14 min 52 sec
C. 14 min 58 sec
D. 16 min 6 sec
E. 16 min 12 sec

Do a more efficient single calculation:

24 min 18 sec is 90% of her exercise time.
When she completes 40% of her exercise session, the readout will indicate 60% of the time.

So we need $$\frac{6}{9} * 24(\frac{18}{60}) = \frac{161}{10} = 16 ( \frac{1}{10}) = 16 (\frac{6}{60}) =$$16 min 6 sec

I guess you have a little flaw somewhere. OA is indeed E (16min 12sec), just saying

Yes, you are right. Thanks for pointing it out. Edited.
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20 May 2016, 12:03
5
1
24 min 18 sec = 1458 sec --> this is 90% of the total workout (w)

.9w = 1458 sec
w = 1620 sec

The readout when she had done 40% of the workout will be 60% of the total

1620*.6 = 972 --> 972/60 = 16 min 12 sec

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Joined: 18 Mar 2015
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06 Jun 2016, 10:13
I did it like this:

If 24 min and 18 seconds is left and 10% is completed then 90% is left.

Therefore, 24 18/60 = 90% x
x = 27 min total time

Then 10% completed = 27 min - 24 min 18 sec = 2 min 42 seconds

Therefore 60% completed = 10% * 6 = 2 min 42 seconds * 6
= (2 + 42/60) * 6 = 162 / 10 = 16 + .2 min = 16 min 20 seconds

= E
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26 Jun 2016, 10:24
2
CoffeeCreamSugar wrote:
Dara ran on a treadmill that had a readout indicating the time remaining in her exercise session. When the readout indicated 24 min 18 sec, she had completed 10% of her exercise session. The readout indicated which of the following when she had completed 40% of her exercise session?

A. 10 min 48 sec
B. 14 min 52 sec
C. 14 min 58 sec
D. 16 min 6 sec
E. 16 min 12 sec

Time remaining when 10% of session completed = 24 mins and 18 seconds.
Let us covert everything in seconds to calculate the total time.

24 mins 18 seconds = 24*60 + 18 = 1440 + 18 = 1458
90% of time = 1458 seconds.

100% of time = 1458*10/9 = 1620 seconds
40% completed = 60% remaining.
Time remaining = 0.6*1620 = 972seconds = 960 + 12 seconds = 16 minutes 12 seconds.

Correct Option: E
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21 Jul 2016, 05:48
8
1
I disregarded the minutes and only focused on the seconds since all answer options have a different seconds count.
18 seconds is 90% --> 20 seconds is 100% --> 60% is 12 seconds --> answer E
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22 Jul 2016, 03:21
she completes 90% work in 1458 seconds (24mins and 12 sec)
therefore to complete 60% work (100% Original work - 40% completed)she requires

60*1458= 972 seconds or 16 mins 12 seconds
90
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07 Aug 2016, 03:31
12
1
This problem can be done mentally without any calculations

Readout indicated 24 min 18 sec when she had completed 10% of her exercise.

This means remaining 90% of the work will take 24 min 18 sec => 30% will take 8 min 6 sec

so 40% completed i.e. 60% remaining of the work will take (24min 18 sec- 8 min 6 sec)= 16min 12 sec.
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08 Sep 2016, 23:40
X = total time

.9x = 24.3 minutes

x = 24.3/.9
x = 24.3 * 10/9 = 243/9 TOTAL TIME

243/9 * 6/10 = 243/15 = 16 1/5 minutes

16 1/5 minutes = 16 minutes + 12 seconds

Easy math takes 30 seconds.

A very simple conversion to memorize that makes these type of problems super intuitive: .1 hours = 6 minutes. Remembering this equation means you don't need to waste time converting the entire thing to seconds as some have done above.
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19 Sep 2016, 09:15
Used the following method:

24 min 18 sec = 10% Completed = 90% remaining
''x'' = 40% Completed = 60% remaining.

Converting the time to seconds: 1458 = 0.9, x = 0.6. Cross multiplying, 1458 x 6/10 = 9/10(x). Solving for 'x', I get 972 secs which is equal to 16 mins 12 secs.
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06 Dec 2016, 19:57
1
convert 24 min 18 sec to min --> 0.18 sec = 0.3 min --> 24.3 min

24.3 min is 90% of the total time --> 24.3 = 0.90x --> x = 27min

Question is asking us what the time will be when the clock she has 60% left to run --> 0.60x27min= 16.2min

0.2x0.60 = 12 sec

E.
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17 Jan 2017, 10:57
I would like an answer from Bunuel right here.
I answered this Q correctly but I dont think that my way of answer is correct.

Let's assume that the 100% of time is an Integer.
Then at 10% of time , x minutes & 42 seconds (as there are 18 seconds remaining) have passed.

So when she will have consumed 40% of her time, there will have passed 4*x minutes + 4*42 seconds.
This solution gives an integer number for minutes for which we do not care about and 4*42 seconds gives us 168 seconds, which is 2 minutes and 48 seconds PASSED in addition to the 4*x minutes.

The only solution that gives us a remainder of X minutes (for which we continue to not care about) and 12 seconds (60-48), is E.

Am I right ? Or I shouldnt have assumed that the total time is an Integer?
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23 Jan 2017, 06:05
3
CoffeeCreamSugar wrote:
Dara ran on a treadmill that had a readout indicating the time remaining in her exercise session. When the readout indicated 24 min 18 sec, she had completed 10% of her exercise session. The readout indicated which of the following when she had completed 40% of her exercise session?

A. 10 min 48 sec
B. 14 min 52 sec
C. 14 min 58 sec
D. 16 min 6 sec
E. 16 min 12 sec

We are given that Dara completed 10% of her exercise session when the readout indicated 24 min and 18 seconds as her time remaining. In other words she had 90% left of her workout at that time. We need to determine the readout after she has completed 40% of her exercise, or when she has 60% left.

We can create a proportion to determine the time when Dara has 60% left. First, let’s convert 24 min 18 sec to minutes.

24 min 18 sec = (24 + 18/60) min = (24 + 3/10) min = 24.3 min

We can also express 90 percent as 90/100 = 0.9 and 60 percent as 60/100 = 0.6. We define x as the number of minutes remaining in her workout when she has 60%, or 0.6, of her workout left to do.

Our proportion is as follows:

0.9/24.3 = 0.6/x

9/243 = 0.6/x

9x = 145.8

x = 145.8/9 = 16.2 min

Thus, x = (16 + 2/10) min = (16 + 12/60) min = 16 min 12 sec

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25 May 2017, 16:40
1
Although I usually tend to rely on the algebraic approach described for this question by other posters, I want to provide an additional approach.

We are told that 90% of the remaining time equals 24 min and 18 seconds.

We can divide this one 90% portion into three 30% portions:

24 min divided by 3 = 3 portions of 8 min

18 sec divided by 3 = 3 portions of 6 sec

Since 30% + 30% = 60%, we then can make the sum of two of the portions to estimate the remaining time when Dara has completed 40% of the exercise session (or the remaining 60%):

(2 portions of 8 min = 16 min) + (2 portions of 6 sec = 12 sec)

Total = 16 min and 12 sec. Option E.

Hope it helps.
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20 Sep 2017, 08:51
1
poppe50 wrote:
I disregarded the minutes and only focused on the seconds since all answer options have a different seconds count.
18 seconds is 90% --> 20 seconds is 100% --> 60% is 12 seconds --> answer E

This approach is incorrect, it gives the correct answer out of luck only because the 60% of the total minutes is an integer.

If you want you can separate them, but should be like this:

(1) 24 mins in 90%. Means that in 60%: 60*24/90 = 16 mins (simplify to calculate that)
(2) 18 secs in 90%. Means that in 60%: 60*18/90 = 12 secs (also simplifying)

if (1) turned out to be a fraction, then the answer would not just rely on the 12 secs you calculated.

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