Question

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?

Answer 1

 For 1AM to noon:  1    2   3  4   5   6  7  8  9  10  11  12   For 1PM to midnight I will write the hours in reverse order:                          12 11 10  9   8   7  6  5  4    3   2    1   Check out the sums:                        --------------------------------------------                          13 13 13 13 13 13 13 13 13 13 13 13 = 13*12 = 156