Aptitude - Clock - Discussion

@ALL.

I AM NEW TO THIS COMMUNITY,
NOW I WANT TO SHARE ABOUT CLOCK,
BEFORE GOING TO ATTEMPT ANY CLOCK PROBLEMS,
1.HOUR'S HAND TAKES.
=============HOURS HAND/ SHORT HAND=============
Time to finish one cycle = 360's.
i.e in 12hrs of time =360 degrees.
Within 1 hour of time = 360/12 =30 degrees.
Which means 60 mins = 30 degrees.
In one minute = 1/2 degree (half degree).
=============MINUTES HAND/ LONG HAND=============
Within 1 hour of time =360 degrees.
Which means 60 mins = 360 degrees.
In one minute = 360/60 = 6 degrees.

I think this stuff will help to solve any clock problem.

Hint : Clock started at noon therefore 10min past of 5 means that the clock time is 4:50
hence, now observe the clock 12(-6),1,2,3,4,5,6,7(-1),8(-2),9(-3),10(-4),11(-5) here - indicates opposite.

So now 4:50 means 4 is hours hand 50 is min hand which is -4.

Therefore 4-4=180(complete cycle). Now answer is (180-(50/2))=155. Why 50/2 means 50 is min covered, we know in 1hr it covers 30 degrees then in 1min it covers 1/2degrees therefore in 50min it covers 50/2 degrees.

12hr=360° so,
1hr=30°
Coming to Question
10 past 5 = 5:10.

Here, from 12 noon to 5 indicate= 5*30=150° This is the angle when Time is exactly 5 o'Clock but,

In this question, Time is 5:10. Now we need to calculate how much extra distance travelled by the hour hand in that 10 min.

Converting 10 min in Hours= 10/60 = 1/6.
The Angle travelled by the minute hand in 10 = 1/6*30= 5°.
So the total Angle= 150°+ 5° = 155°.

Solution.

A clock is a circular shape and is 360°.
A clock is divided into 12 sections or 12 hrs.
Every sections or hour is 30°.

i.e 360°/12 = 30°.

So, 1 hr = 30°.
we get, 5hrs = 30°X5 = 150°.

1 min = ° ?
As 1hr = 30°.
1 min = (30°/ 60) =(1/2)= 0.5°.
So, 10 mins = 10 X 0.5° = 5°.
Then, 5 hrs 10 mins = 150°+5° = 155°.

The question asked is not for angle b/w hours hand and minutes hand.the question is:how much distance only hours hand rotated from noon...
from 12 to 5:00 the hours hand rotated is 150degree.use the formula 30h-(11/2)*m=theta; now how much is the hours hand rotated in in 10min. i.e..for 1hour..it will make 30degree...for 10min..it will make 5degree. therefore 150+5=155

It is too much simple.do not complicate it.

Just convert hours into minutes..so, we can say.

12 hours = 360°.

Convert 12 hours into minutes= 720 minutes,
and 5 hours and 10 minutes= 310 minutes,


So simple formula fir that is;
720 minutes = 360°
310 minues = (?).

So,
Cross multiply it and then divide.

(310 * 360)/720.
It become 111,600/720= 155°.

For hour hand(HH),we have a notation i.e., 360/12 and for min hand (MH) it's 360/60.
360/12=30° ---> 1.

Now,as given in the problem..
10 past 5 i.e, it's 5:00 and extra 10 min completed overall...
So, it's 5:00+00:10=5:10.
It's also written as..5+(10/60).
5+(1/6)..= 31/6---> 2eq.

Finally ,from 1eq & 2eq..
30° * 31/6 = 155°

Hello. When I read this question and I drew 5.10 in the paper. I thought that we have to find the angle between minute hand and hour hand that makes 5.10, therefore I found out the answer was 90 degrees.

But the problem is I don't understand " a clock is started at noon". What does it mean? Could you guys explain for me, please!

The clock starts at noon till 5:10.
Hour hand has travelled 5 hours,
Therefore 5*30=150.

In the Remaining 10 min hours, the hand must have travelled some more distance.
Therefore 10min= 10/60 (converting it into hours)=1/6,
Now 1/6*30 ( because hour hand makes 30° angle in every hour)=5°
Therefore add 150+5=155°.

At n'o clock the angle of hour hand from vertical is 30 n; speed of hour hand is 5 degree per minute; speed of minute hand is 6 dpm.

At 5.10 angle of hour hand from vertical 5*30+0.5*10 = 155 degree.

Angle of minute hand from vertical 6*10 = 60;

Angle between hour and minute hand = 155-60 = 96.

Reflex angle 360-96 = 264.