Answer :
Answer:
the square number = 36
Step-by-step explanation:
nth term = n(n + 1) / 2
let's begin the series with n = 1
series would be written as:
1, 3, 6, 10, 15, 21, 28, ....
at 5th and 6th terms are:
15 and 21 which add up to make a square number i.e. 36
