Question

Answer to this questions Please *Question 8*
A clock strikes once at 1 o’clock (am or pm), twice at 2 o’clock (am or pm), thrice at 3 o’clock (am or pm) and so on. How many times will it strike in 24 hours?
Select one:
1. 78
2. 136
3. 156
4. 196

Answer 1

1+2+3+...+n = n(n+1)/2

so, from 1:00 to 12:00 it strikes 12*13/2 = 78 times

and it does that twice in 24 hours.

Answer 2

156