Question

First triangular number is(a) 3(b) 6(c) 10(d) 15.​

Answer 1

Answer:

15 or 3 or 6 or 10 I don't know but 15 will it

Answer 2

Answer:

This is the Triangular Number Sequence: 1, 3, 6, 10, 15, 21, 28, 36, 45, ...