Q. How many times the hand of a clock are at right angle in a day?

Explanation by: Madhu

We know that the hands of a clock are at right angle twice in every hour but between 2 and 4 O' clock there is a common position at 3 O' clock and also between 8 and 10 O' clock there is common position at 9 O' clock.

So, they are at right angles 22 times in 12 h and therefore, in 24 h or in a day they are at right angle 44 times.