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:
154 comments Page 7 of 16.
Yashpal said:
9 years ago
Agree with you @Nitin.
The correct answer is A.
The correct answer is A.
Gjm said:
9 years ago
Simple friends time 7 am to 4.15 pm.
1st we take time 7am to 8am that means 60 min but give its gain 5 sec in 3 min so 60/3 = 20 mins.
Then 20 min * 5 sec = 100 sec that means 1.40 min per 1 hour so now we calculate 7am to 4:15pm, 9 hours = 15 min 4:15 - 0:15 = 4 pm.
1st we take time 7am to 8am that means 60 min but give its gain 5 sec in 3 min so 60/3 = 20 mins.
Then 20 min * 5 sec = 100 sec that means 1.40 min per 1 hour so now we calculate 7am to 4:15pm, 9 hours = 15 min 4:15 - 0:15 = 4 pm.
Vivek said:
9 years ago
No Need to use such a long method.
In 3 mins it's gaining 5 sec.
Io in 1 min the gain take = 5/3.s
And in 60 min it's going to gain = (5/3) * 60= 100 s.
Now the difference between two times is 9 : 15 hrs.
And in 9 hrs it's going to gain 100 * 9 = 900 s.
900 /60 = 15 min.
So at 4 : 15 it's already 15 min ahead so real time will be 4.
In 3 mins it's gaining 5 sec.
Io in 1 min the gain take = 5/3.s
And in 60 min it's going to gain = (5/3) * 60= 100 s.
Now the difference between two times is 9 : 15 hrs.
And in 9 hrs it's going to gain 100 * 9 = 900 s.
900 /60 = 15 min.
So at 4 : 15 it's already 15 min ahead so real time will be 4.
Tejas said:
9 years ago
Total hours with error from 7 am to 4:15 pm = 9 h 15 min = 33300 secs.
Total original hours from 7 am to 4 pm = 9 hrs = 32400 secs.
Therefore, 33300 - 32400 = 900.
900/60 = 15 min.
Total original hours from 7 am to 4 pm = 9 hrs = 32400 secs.
Therefore, 33300 - 32400 = 900.
900/60 = 15 min.
Aneesha said:
9 years ago
How did you get 37\4?
Prateek said:
9 years ago
Thank you so much @Sundar.
Wadbor said:
9 years ago
@Khalid
You got it right in a simple way. For 9hr it gains 15min so 9hr 15min minus gain of 15min will give 9hr correct time.
You got it right in a simple way. For 9hr it gains 15min so 9hr 15min minus gain of 15min will give 9hr correct time.
Srikanth.s said:
9 years ago
3 Min = 5 sec fast,
1 Hour = 1.66 Min fast (100 sec),
Normally, 9 hr has = 9 * 60 min i.e 540,
For error, 9 hr has = 9 * 61.66 min i.e 554.94,
So, 554.94 - 540 = 14.94 min,
Hence the answer is 4.
1 Hour = 1.66 Min fast (100 sec),
Normally, 9 hr has = 9 * 60 min i.e 540,
For error, 9 hr has = 9 * 61.66 min i.e 554.94,
So, 554.94 - 540 = 14.94 min,
Hence the answer is 4.
Khanam said:
9 years ago
Please explain me in clear and easy form I didn't understand this.
Omi said:
9 years ago
Wrong answer. The correct answer will be A.
7 am to 4:15 pm = 9h 15 minutes.
3 minutes -----> 5 seconds gains.
60 minutes -----> 100 seconds gains.
So, 9h + 15 minutes -----> 9 * 100,
= 900 seconds + (15/3) * 5 = 925 seconds gains.
So, 925 secs = 185/12 minutes.
So, the answer is A.
7 am to 4:15 pm = 9h 15 minutes.
3 minutes -----> 5 seconds gains.
60 minutes -----> 100 seconds gains.
So, 9h + 15 minutes -----> 9 * 100,
= 900 seconds + (15/3) * 5 = 925 seconds gains.
So, 925 secs = 185/12 minutes.
So, the answer is A.
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