How many times are the hands of a clock at right angle in a day?

Correct Answer: 80 deg

Explanation:

As minute hand covers, 60 degrees

Minute hand covers 4800/60 = 80°

Correct Answer: 88 deg

Explanation:

In one hour, the minute hand gains 330° over the hour hand. i.e., 60 minutes, the minute hand gains 330° over the hour hand. ∴ In 16 minutes, the minute hand gain over the hour hand by fraction numerator 330 degrees over denominator 60 end fraction cross times 16 degree equals 88 degree

Correct Answer: (49 +1/11) min past 9

Explanation:

To be together between 9 and 10 o'clock, the minute hand has to gain 45 min. spaces.
55 min. spaces gained in 60 min.

 

45 min. spaces are gained in  60 55 × 45 min  or  49 1 11min

Correct Answer: 16 4/11

Explanation:

At 3 o'clock, the minute hand is 15 min. spaces apart from the hour hand.
To be coincident, it must gain 15 min. spaces.55 min. are gained in 60 min.
15 min. are gained in
= (60/55 x 15)min
=16+4/11
The hands are coincident at 16 + 4/11 min past 3

Correct Answer: 172.5 degrees

Explanation:

The minute hand angle is the easiest since an hour (i.e. 60 minutes) corresponds to the entire 360 degrees, each minute must correspond to 6 degrees. So just multiply the number of minutes in the time by 6 to get the number of degrees for the minute hand.
Here 15 minutes corresponds to 15 x 6 = 90 degrees

Next, you have to figure out the angle of the hour hand. Since there are 12 hours in the entire 360 degrees, each hour corresponds to 30 degrees. But unless the time is EXACTLY something o'clock, you have to write the time as a fractional number of hours rather than as hours and minutes.
Here the time is 9:15 which is (9 + 15/60) = 37/4 hours. Since each hour corresponds to 30 degrees, we multiply 30 to get (37/4)(30) = 277.5 degrees.

Since the hour hand is at 277.5 degrees and the minute hand is at 90 degrees, we can subtract to get the angle of separation. 277.5 - 90 = 187.5 =~ 360 - 187.5 = 172.5 degrees.

Correct Answer: 90 degrees

Explanation:

Minute hand covers 5400/60 = 90°

Correct Answer: 3:16 4/11

Explanation:

Coincide means 00  angle.

This can be calculated using the formulafor time A to B means  [11m/2 - 30 (A)]

Here m gives minutes after A the both hands coincides.

Here A = 3, B = 4

0 =11m/2 ?30 × 3
11m = 90 × 2 = 180
m= 180/11 = 16 ⁴/₁₁

So time = 3 : 16 ⁴/₁₁

Correct Answer: 37.5

Explanation:

Angle between hands of a clock

 

When the minute hand is behind the hour hand, the angle between the two hands at M minutes past H 'o clock

 

=>  30 H - M 5 + M 2 degrees

 

Here H = 4, M = 15 and the minute hand is behind the hour hand.

 

Hence the angle

 

 = 30[4-(15/5)]+15/2 = 30(1)+7.5 = 37.5 degrees

Correct Answer: 66 sec

Explanation:

For ticking 6 times, there are 5 intervals.

Each interval has time duration of 30/5 = 6 secs

At 12 o'clock, there are 11 intervals,
so total time for 11 intervals = 11 x 6 = 66 secs.

Correct Answer: 3:49 1/11

Explanation:

On straight line means 180 degree angle.
180 = 11/2 min ? 30 hrs
180 = 11/2 m ? 30 × 3
180 = 11/2 m ? 90
(180 + 90) 2 = 11 m
m = 540/11 = 49 1/11 minutes.