Question 1169268
<br>
The month-by-month sequence, in units of P100,000, is<br>
1, 2, 3, ..., 11, 12<br>
The sum is (number of terms) times (average of first and last):<br>
{{{12*((1+12)/2) = (12*13)/2 = 78}}}<br>
ANSWER: 78 times P100,000, or P7,800,000.<br>