Find the number of terms of the given AP:
Formula to find nth term of arithmetic progression is
'a1' is the first term,
'd' is the common difference,
'n' is the number of terms,
'tn' is the nth term.
Given, a1=7 , a2=13, tn=205
d = a2 - a1 = 13 - 7 = 6
Substituting the values in the formula tn=a+(n−1)d to find nth term of arithmetic progression, we get
Therefore, there are 34 terms in the given arithmetic progression.