Determining as a function of n how often the statement incrementing the variable count is performed

Question

Ok so I\'m new to analyzing algorithms and would really appreciate any helpful tips that can be shared on how to go about this. I am trying to determine how many times count

Answer 1

1

1+2 = 3

1+2+3 = 6

1+2+3+4 = 10

1+2+3+4+5 = 15

It is only me who sees the pattern? :-)