Find the 14-th and 15-th triangular numbers, and find their sum. Verify the Statement 8 for this sum.
The 14th and 15th triangular numbers are:
14th triangular number = 1 + 2 + 3 + 4 + … + 14 = 105
15th triangular number = 1 + 2 + 3 + 4 + … + 14 + 15 = 120
Sum of the 14th and 15th triangular numbers = (14 + 1)2 = 225
Here, 105 + 120 = 225
Hence, statement 8 is verified.