# 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:

152 comments Page 1 of 16.
Khairul Basar said:
4 weeks ago

Gain:

3 minutes 5 sec,

15 minutes 25 sec,

30 minutes 50 sec,

60 min( 1 hour) 100 sec.

Then, 7 to 4:15 - 9 hours 15 minutes.

Per hour 100 sec= 900.

And 15 minutes 25 sec.

Total - 925 sec.

925 sec รท 60 = 15 minutes.

(15 mins is extra).

9 hours 15 - 15 minutes 9 hours.

7 AM to 4 PM (9 hours).

So, the answer is 4 PM.

3 minutes 5 sec,

15 minutes 25 sec,

30 minutes 50 sec,

60 min( 1 hour) 100 sec.

Then, 7 to 4:15 - 9 hours 15 minutes.

Per hour 100 sec= 900.

And 15 minutes 25 sec.

Total - 925 sec.

925 sec รท 60 = 15 minutes.

(15 mins is extra).

9 hours 15 - 15 minutes 9 hours.

7 AM to 4 PM (9 hours).

So, the answer is 4 PM.

(11)

Dhanush said:
4 weeks ago

For 3 mins it gains 5 seconds.

Then for 925 minutes (9hr 15 min) it gains 15 mins 25 seconds.

So, subtract 15 mins 25 seconds from 4:15.

We will get 3:59:35 which is 59* (7/12) mins past 3.

Then for 925 minutes (9hr 15 min) it gains 15 mins 25 seconds.

So, subtract 15 mins 25 seconds from 4:15.

We will get 3:59:35 which is 59* (7/12) mins past 3.

(9)

Khushpreet kaur said:
3 months ago

Thank you everyone for explaining the answer.

(2)

Abhishek Gupta said:
4 months ago

It gains 5 seconds in 3 minutes.

3min = 5seconds

3min = 1/12 min

1min = 1/36 min

Let correct watch shows time which is x min ahead of 7 am.

Then minutes gained by faulty clock = x/36minutes.

So, the faulty clock is ahead of 7 am by (x + x/36)min or 37x/36 min.

but in question, it is given faulty clock shows 4.15 pm which is (9*60+15)min or 555min ahead of 7 am.

So,

37x/36 = 555

x = 540min or 9 hrs

So, the correct time is 7 am + 9hr = 4 pm.

Note: We have to calculate the time gained by the faulty clock in terms of the correct clock not in terms of the faulty clock time given in the question

3min = 5seconds

3min = 1/12 min

1min = 1/36 min

Let correct watch shows time which is x min ahead of 7 am.

Then minutes gained by faulty clock = x/36minutes.

So, the faulty clock is ahead of 7 am by (x + x/36)min or 37x/36 min.

but in question, it is given faulty clock shows 4.15 pm which is (9*60+15)min or 555min ahead of 7 am.

So,

37x/36 = 555

x = 540min or 9 hrs

So, the correct time is 7 am + 9hr = 4 pm.

Note: We have to calculate the time gained by the faulty clock in terms of the correct clock not in terms of the faulty clock time given in the question

(4)

Satvik said:
6 months ago

3 min - 5 sec.

30 min - 50 sec.

60 min - 100 sec. [ 1 hour - 100 sec]

9 hours - 900 sec [900 sec = 15 min ].

The clock is showing 4:15 and we know that it gained 15 mins

Therefore it must the real-time is 4 pm.

30 min - 50 sec.

60 min - 100 sec. [ 1 hour - 100 sec]

9 hours - 900 sec [900 sec = 15 min ].

The clock is showing 4:15 and we know that it gained 15 mins

Therefore it must the real-time is 4 pm.

(78)

Aanch said:
10 months ago

The right answer is option A.

(14)

Rama said:
2 years ago

Gained time = 925 secs ==> 15 mins and 25 secs.

From 4.15 - 15 mins ==> 4 (only subtracting the 15mins).

From 4 - 25 secs ==> converting in fraction (25/60) ==> need to subract 25 sec ie: remaining of 35/60,

So,3 hrs and 59 mins and 35/60 ==> 59 mins 7/12 past 3. So, the answer is A.

From 4.15 - 15 mins ==> 4 (only subtracting the 15mins).

From 4 - 25 secs ==> converting in fraction (25/60) ==> need to subract 25 sec ie: remaining of 35/60,

So,3 hrs and 59 mins and 35/60 ==> 59 mins 7/12 past 3. So, the answer is A.

(83)

Sonia said:
2 years ago

9 hr 15 min= 555min.

Watch gain 5 sec in 3 min so, we will check how many minutes gain 5 sec.

So, 555/3= 185min

185 min gains how many sec=185 multiplies with 5 = 925 sec.

And convert 925sec into min= 15.41 min( gain a minute, so we have to minus it from the time shown)

Now 4.15 was showing on the clock now minus 15min from it= 4pm.

Watch gain 5 sec in 3 min so, we will check how many minutes gain 5 sec.

So, 555/3= 185min

185 min gains how many sec=185 multiplies with 5 = 925 sec.

And convert 925sec into min= 15.41 min( gain a minute, so we have to minus it from the time shown)

Now 4.15 was showing on the clock now minus 15min from it= 4pm.

(79)

Kiran said:
2 years ago

5sec gains in 3min.

5sec =3 min.

Multiply with 20.

100 sec gains in 60min(100sec = 60min).

Then 300sec = 180min.

Converting 300 sec into min is 5min.

180min is 3 hrs.

So it gains 5min in 3hrs.

We know that from 7 to 4 .15min is 9hrs 15min.

It gains 5min in 3hrs then for 9hrs it gains 15min so subtract 15 min from the time.

Then the answer is 4'pm.

5sec =3 min.

Multiply with 20.

100 sec gains in 60min(100sec = 60min).

Then 300sec = 180min.

Converting 300 sec into min is 5min.

180min is 3 hrs.

So it gains 5min in 3hrs.

We know that from 7 to 4 .15min is 9hrs 15min.

It gains 5min in 3hrs then for 9hrs it gains 15min so subtract 15 min from the time.

Then the answer is 4'pm.

(54)

Puppireddy Sai Krishna said:
2 years ago

If the clock gains 5sec for every 3mins it travels 9hrs and 15mins i.e., 9.25hrs.

Let the actual clock goes 'x' 3mins.

Then the clock which gains 5 secs for every 3 mins will go (3mins)x + (5secs)x =9.25hrs

=> (3+ (5/60))x = 9.25*60.

So x= 180mins,

i.e., x=3hrs,

So the actual clock goes 3x i.e., 9hrs.

So, 9hrs from 7 a.m. is 4 p.m.

Let the actual clock goes 'x' 3mins.

Then the clock which gains 5 secs for every 3 mins will go (3mins)x + (5secs)x =9.25hrs

=> (3+ (5/60))x = 9.25*60.

So x= 180mins,

i.e., x=3hrs,

So the actual clock goes 3x i.e., 9hrs.

So, 9hrs from 7 a.m. is 4 p.m.

(8)

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