Question 1086346
Starting at midnight the clock strikes 12, then 1, 2, etc. until noon when it strikes 12 again. Then through 1,2, .. 11. 
So find the sum from 1 to 12 and then double it.
{{{N=(12(12+1))/2=6*13=78}}}
So then,
{{{N[t]=2*78}}}
{{{N[t]=156}}}