Aptitude - Clock - Discussion
Discussion Forum : Clock - General Questions (Q.No. 4)
4.
A watch which gains 5 seconds in 3 minutes was set right at 7 a.m. In the afternoon of the same day, when the watch indicated quarter past 4 o'clock, the true time is:
Answer: Option
Explanation:
| Time from 7 a.m. to 4.15 p.m. = 9 hrs 15 min. = | 37 | hrs. |
| 4 |
3 min. 5 sec. of this clock = 3 min. of the correct clock.
 |
37 | hrs of this clock = | 1 | hrs of the correct clock. |
| 720 | 20 |
| |
37 | hrs of this clock = |  |
1 | x | 720 | x | 37 |  |
hrs of the correct clock. |
| 4 | 20 | 37 | 4 |
= 9 hrs of the correct clock.
The correct time is 9 hrs after 7 a.m. i.e., 4 p.m.
Discussion:
156 comments Page 15 of 16.
Sundar said:
2 decades ago
To: Nitin
You are wrong. The given answer is correct. Don't get confused.
Let me explain in simple manner:
Error Clock :: Original Clock
3 min 5 sec :: 3 min
185 sec :: 180 sec
[9 hr 15 min = 555 min = 33300 sec]
33300 sec :: (180/185 x 33300) sec
33300 sec :: 32400 sec
333000sec = 9 hrs 15 min :: 32400 sec = 9 hrs [:. 32400/3600 = 9]
So,
Time passed by Error clock = 9 hrs 15 min.
Time passed by Original clock = 9 hrs.
Therefore, 9 hrs after 7 am is 4 pm.
Note: What was wrong in Nitin's explanation?
555/3 <--- Problem is here.
It should be
555 min/3 min 5 sec [or] 33300/185
Please think twice before solve problem. Hope this will help you. All the best!
You are wrong. The given answer is correct. Don't get confused.
Let me explain in simple manner:
Error Clock :: Original Clock
3 min 5 sec :: 3 min
185 sec :: 180 sec
[9 hr 15 min = 555 min = 33300 sec]
33300 sec :: (180/185 x 33300) sec
33300 sec :: 32400 sec
333000sec = 9 hrs 15 min :: 32400 sec = 9 hrs [:. 32400/3600 = 9]
So,
Time passed by Error clock = 9 hrs 15 min.
Time passed by Original clock = 9 hrs.
Therefore, 9 hrs after 7 am is 4 pm.
Note: What was wrong in Nitin's explanation?
555/3 <--- Problem is here.
It should be
555 min/3 min 5 sec [or] 33300/185
Please think twice before solve problem. Hope this will help you. All the best!
(1)
AKHIL said:
2 decades ago
NITIN CREATE CONFUSION
Sundar said:
2 decades ago
@Archana
It is simple yaar.
9 hrs = (9 x 60) = 540 mins
9 hrs 15 min = (540 + 15) = 555 min.
Now, convert 555 mins to hrs by dividing it by 60 (bcz 60min = 1hr) ok.
Therefore, 555/60 = 37/4 hrs.
That's all. Hope this help you. Have a nice day!
It is simple yaar.
9 hrs = (9 x 60) = 540 mins
9 hrs 15 min = (540 + 15) = 555 min.
Now, convert 555 mins to hrs by dividing it by 60 (bcz 60min = 1hr) ok.
Therefore, 555/60 = 37/4 hrs.
That's all. Hope this help you. Have a nice day!
Archana said:
2 decades ago
Can anyone plz tell me how we got below line?
9 hrs 15 min. = 37/4 hrs.
9 hrs 15 min. = 37/4 hrs.
Jimeet said:
2 decades ago
A watch which gains 5 seconds in 3 minutes was set right at 7 a.m?????? what does it actually means??...i had solved it by d way as nitin described..so wts the correct answer,as they hav ignored the 25secs and according to them correct time is 4....wt abt 25 sec....
Smartsuru said:
2 decades ago
A watch which gains 5 seconds in 3 minutes was set right at 7 a.m? what does it actually means?
Ans: Whenever a original clock runs for 3 min (180 sec) the given clock will run 3 min 5 sec (185 sec).
Ans: Whenever a original clock runs for 3 min (180 sec) the given clock will run 3 min 5 sec (185 sec).
Nitin said:
2 decades ago
From 7am to 4:15pm the time traveled will be 9 hours and 15 min.
So in minutes it will be (9*60)+15=540+15=555
After every 3 min the clock will add 5 second,so in 555 min no of
seconds that will be added=(555/3)*5=925 seconds=925/60min=15min and 25sec
so the correct time will be=CURRENT TIME(that is 4:15pm)-(15min and 25 sec)
=3:59:35pm
35 seconds in min-->35/60=7/12min
so the correct answer must be 59(7/12) which is ""A""
[But this is wrong, read Sundar's explanation given below]
So in minutes it will be (9*60)+15=540+15=555
After every 3 min the clock will add 5 second,so in 555 min no of
seconds that will be added=(555/3)*5=925 seconds=925/60min=15min and 25sec
so the correct time will be=CURRENT TIME(that is 4:15pm)-(15min and 25 sec)
=3:59:35pm
35 seconds in min-->35/60=7/12min
so the correct answer must be 59(7/12) which is ""A""
[But this is wrong, read Sundar's explanation given below]
Shyam said:
2 decades ago
why 720/37?
Vinu said:
2 decades ago
Any body understand last step? can you explain?
Nitesh Nandwana said:
2 decades ago
@Saranya
(3/60)+(5/(60*60)) = 185/3600 = 37/720.
185, it is simple calculation babes.
(3/60)+(5/(60*60)) = 185/3600 = 37/720.
185, it is simple calculation babes.
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