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 6 of 16.
Jayasree said:
8 years ago
Consider the ratio of the speed of original clock : error clock;.
By the time original clock covers 180 secs, error clock covers 185 secs.
therefore speed ratio is 180(original) : 185 (error).
==> 36:37.
Error clock covers 9 hours 15 mins= 9 1/4 hours = 37/4 hours.
Now solving by ratio proportion,
Speed --- time covered(in hours)
37 --- 37/4 ---------> Error clock
36 --- ? ---------> Original clock
Time covered by original clock is ==> 37/4 * 36/37.
==>9 hours i.e, clock shows at 4.00 pm.
By the time original clock covers 180 secs, error clock covers 185 secs.
therefore speed ratio is 180(original) : 185 (error).
==> 36:37.
Error clock covers 9 hours 15 mins= 9 1/4 hours = 37/4 hours.
Now solving by ratio proportion,
Speed --- time covered(in hours)
37 --- 37/4 ---------> Error clock
36 --- ? ---------> Original clock
Time covered by original clock is ==> 37/4 * 36/37.
==>9 hours i.e, clock shows at 4.00 pm.
Vasundhara said:
8 years ago
At a railway station, a 24-hour watch loses 3 min in 4 hours. If it is set correctly on Sunday noon when will the watch show correct time?
Please give me the solution.
Please give me the solution.
Vijay Ramanathan said:
8 years ago
I agree with the Mamta's Explanation. Thanks @Mamta.
Praveen said:
8 years ago
@Sundar.
How it should be 555 min/3 min 5 sec [or] 33300/185"?
It must be divided by 3min right, not 3 min 5 sec.
How you are saying it must be divided by 3min 5 sec?
How it should be 555 min/3 min 5 sec [or] 33300/185"?
It must be divided by 3min right, not 3 min 5 sec.
How you are saying it must be divided by 3min 5 sec?
Sushma said:
8 years ago
Nice explanation, Thank you @Sundar.
Ashok Apple said:
8 years ago
Thank you @Natasha.
Rijas Das said:
9 years ago
Why are you calculating it in the hour? why not in minutes?
Both the answers are different. Make it clear.
Both the answers are different. Make it clear.
Durgesh said:
9 years ago
A clock is set right at 10 a.m the clock gains 10 minutes in 24 hours .what will be the true time when the clock indicates 3 p.m the following day?
Please solve it.
Please solve it.
Sarthak said:
9 years ago
185 seconds to 9hr 15 minute how?
Yashpal said:
9 years ago
You are totally wrong @Gjm.
You can't multiple two different units of time without converting them i.e. 20 min * 5 sec = 100 sec is not possible it could be (20 min/60) sec * 5 sec = whatever.
You can't multiple two different units of time without converting them i.e. 20 min * 5 sec = 100 sec is not possible it could be (20 min/60) sec * 5 sec = whatever.
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