Aptitude - Clock - Discussion

Discussion Forum : Clock - General Questions (Q.No. 10)
10.
At 3:40, the hour hand and the minute hand of a clock form an angle of:
120°
125°
130°
135°
Answer: Option
Explanation:

Angle traced by hour hand in 12 hrs. = 360°.

Angle traced by it in 11 hrs = 360 x 11 ° = 110°.
3 12 3

Angle traced by minute hand in 60 min. = 360°.

Angle traced by it in 40 min. = 360 x 40 ° = 240°.
60

Required angle (240 - 110)° = 130°.

Discussion:
43 comments Page 1 of 5.

Philippine Science Student (Andrei) said:   8 years ago
Let x be the minute hand.

And x/12 the hour hand.

Since the hour hand moves 5 minutes spaces every 160 minutes.

That means it moves 1 minute space every 12 minutes. And also there are 360 degrees in a clock and 60 minutes.

That means a minute is equal to 6 degrees. It is mentioned that it's 40 minutes after 4.

So, let's first get the distance of the hands in minutes spaces.

= 40-(40/12)+15.

Since the time is after 4 the hour hand is 20 minutes after 12.

= 40-18 1/3.

= 21 2/3.

= 21 2/3 x 6 = 130.

It's 130 degrees apart.

AnonB said:   8 years ago
I think the answer should be less than 130 degrees.

Because, here minute hand is at "8" and hour hand is not exactly at "3". The hour hand is slightly shifted past "3". So, slightly reduction in degrees. But not exactly 130 degrees.

Am, I right?

Yuga said:   1 decade ago
Angle traced in 12 hours = 360 degrees.

Hence for, 3 hours and 40 minutes.

Convert 3 hours into minutes 3 hours* 60 minutes = 180 minutes.

Now, just add 40 minutes with 180 minutes total of 220 minutes.

Now divide 220/60 = 11/3.
(2)

Gaurav said:   8 years ago
At 3:40,

Degree rotated by minute hand 6 deg/min = 40 * 6. ie: 240 deg.

Degree rotated by hour hand 0.5 deg/min = 0.5 * 40. ie: 20 deg + 90 deg (angle between hour hand 3 from 12).

Difference = 240 - (20+90) = 130 deg.

Aravind said:   4 years ago
This will bring 140.

The hour hand will be between 3 to 4.
The minute hand will be at 8 because of 40 min.
8-7
7-6
6-5
5-4.

Totally 4*30 =120 degree.
And
Then hour hand will be 40/2 20 degrees.
120 + 20.
=> 140°
(2)

Sayali said:   8 years ago
Solutions given by the site are bit difficult to understand or the approach is bit different, but with basics in your hand problems can be solved faster and don't always accept the system's solutions.

Khem Raj said:   1 decade ago
I think this is the best site to prepare for any aptitude test.I will tell my friends abount this site who are unknown to this site.Because i was also unknown to this site upto this time.

Venki said:   1 decade ago
First consider for hours hand.

1hr of hand movement = 30 degrees.

Next for min hand.
5 min of min hand = 30 degrees.

Hence for angle between them subtract the total angle made by them.

Sangavi said:   7 years ago
3:20.

Formula is((11/2)*M-30(H)).

Here H=3 and M=20.then substitute in formula.

((11/2)*20-30(3)).
((110-90))=20.

The angle in between an hour and minute is 20 degree.

Mehboob said:   2 years ago
Convert 3hours into min.
60 * 3 = 180.
Then add 40min.
40+180 = 220.

Then 1 hour is equal to 30degre.
30 * 3 = 90.

Then subtract 220 - 90= 130 will be the answer.
(6)


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