Question

the clock strikes only for hour. if strikes one time for 1 hour , two time for 2 hour and so on . it strikes............... time in 24 hours

Answer 1

1+2+3+4+5+6........+12
but a day has 24 hours
so ,
2 (1+2++3+4+..+12)
the formula is

n(n+1)/2
here n = 12
= 12(12+1)/2
= 12(13)/2
= 6(13)
=78

so, 78 *2
= 156 times