Now that's what I call a SequenceOfThreeNumbers Fallacy...

 

Variable Description: (All in int)
[Variable | Purpose]
i, j: Loop variables
first: For first multiple
second: For second multiple
k: For calculating no. of terms of a particular no. in the second multiple
diff: Increases in A.P. and added to k
sum: For showing individual sum
sum1: For showing total sum