A clock strikes once at 1 O’clock, twice at 2 O’clock,

A clock strikes once at 1 O’clock, twice at 2 O’clock, thrice at 3 O’clock and so on. How many times will it strike in 24 hours?

As per the given above question , we know that

2 × sum of natural numbers upto n =	2 × n × (n + 1 )		.
	2

Number of strike = 2( 1 + 2 + 3 + … … + 12) =	2 x 12 x (12 + 1 )	= 12 x 13 = 156	.
	2

Thus ,it will strike 156 times in 24 hours .