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?
A
78
B
136
C
156
D
196
Correct Answer: 156
1 + 2 + 3 + 4 + .......... + 12 = 78 12 + 12 = 24 hours so 78*2 = 156