Aptitude - Clock - Discussion

Simply speaking, every 15 min (4/Hour) is right angle except at 6 & 12, AM PM both. (24 x 4) - 4.

At 10 o clock, we can't observe a right angle. Right?

At what time 90 degrees formed 11 and 12? Anyone, please explain.

It's awesome. Thanks all for explaining.

=> When Hour and Min Hand are 15 mins and 45 mins away from each other, they form a right angle. So basically in every 60 min SPACES(not mins), they form right angles 2 times.

=> Let's start from 12 AM (0 degree angle).
55 min spaces are covered in 60 mins.
So 60 min spaces are covered in?
=(60*60)/55 mins.

> In a day there are 24 hours = 24 x 60 mins,
So how many such 60 min spaces exist in a day.
= ( (24*60) / ((60*60)/55)) = 22
So, 22*2 = 44 times they form a Right angle in a day.

The answer is 22 times.

Every hour, 2 right angles are formed between the hands. But because minute hand crosses hour hand every 55 mins, every hour, there is a 5-minute lag. For 24 hours, the lag is 24x5= 120 mins i.e. 2 hour lag - a loss of 4 right angles in 24 hours.

So: 24x2 - loss = 44.

The number of degrees that the hour hand of a clock moves through between 1:00 PM to 3:30 PM in of the same day is?

Can anyone solve this.

I am giving SIMPLE EXPLANATION.

Yes, it's right that in each hour clock generally makes 2 right angles.

But between 2-4 it makes only 3 instead of 4 because, at 3 o clock, the right angle is common to both intervals of (2-3) and (3-4).

Similarly, 8-10 make 3 right angles.

ie, 22 right angles in 12 hours and 44 in a day.

I didn't understand the explanation. Can anyone help me?