Aptitude - Clock - Discussion

Actually Sundar's explanation is correct.

Don't get confusion. The question is about two clocks (accurate clock and the error clock). So many of you confused.. 59 7/12 past 3 is wrong because, you are considering only one clock.. you went wrong while dividing 555 minute by 3.. in reality... 555 minutes are passed in ERROR CLOCK,

So you must divide 555 by 3 min 5 seconds (OR 555*60=33300 seconds divided by 3*60+5=185 seconds) Then you will get the right answer.

x+((x*5)/(3*60))=555*60.
Find x?

x is the seconds between 7am and correct time.
555 is minutes between 7am and wrong time.

Find x and convert to hrs getting x as 32400 sec.
Then converted to hrs.

32400/3600= 9 hrs.

7am+ 9hrs=4PM.

For 9 hrs its 9x60=540 minutes.
In 540 minutes (540/3)=180 i.e 180 times 3 minutes are there for each 3 minute it is 5 second then 180x5=900 seconds 900/60=15 minutes, which is extra to be subtracted from 4.15 pm. So 4 is the answer.

We do it in this way.

3min=5sec.
1hr=100sec.
9.15hr=925sec.

You made mistake now in division
925/60=15 min.
But ans will be 925/60=15.416667 or 15 7/12

So the excess time is 15 min.

So, 9.15 hr - 15min7/12sec = 59 7/12min past 3 hr.

@Mamta.

Thanks. Your explanation is good and very easy to understand.

Hey friends can't we do in this way.

3min=5sec.

1hr=100sec.

9. 15hr=925sec.

925/60=15 min.

So the excess time is 15 min.

So, 9.15 hr-15min = 9hr.

i.e. 4 P.M.

Hey if looking pointwise wats wrong in this :-
3 min = 5 sec

total min. covered uptill 9:15 is : 555 min. =5/3 * 555 == 925 sec (toatl error)

Now converting into min:- 925/60= 15 5/12 min

Subtracting from the time right now to get actually what the error:- 4 hrs 15 min- 15 5/12 min

Ans:- 59 7/12min past 3 hr

Can anybody explain clearly how 37/4hrs of wrong clk converted to 9hrs of correct clock.

Given->
for 185 seconds of wrong time 180 seconds is correct time;
So 33300 seconds of wrong seconds what will be the correct seconds?

Surely its 180*33300/185 ie 32400 seconds. ie 9 hrs (32400/3600).

To get the correct time add 9 hrs to 7.00 am ie 4.00 pm
****************************************************************
How I got 33300 seconds ?

From 7.00 am to 4.15 pm its 9 hrs and 15 seconds ie 9*60*60 + 15*60 seconds =33300 seconds )

Is it simple ?

@Meenu

If Error-Clock passes 185 secs then Original-Clock passes 180 sec only.

So, If Error-Clock passes 33300 secs (ie 9 hr 15 min) then Original-Clock passes 32400 sec only.

Hope you got it. Have a nice day!