3,9,15 what is the 36th term

firstly, we have to find the difference

the diff is 6

we apply the concept diN+0

Di is difference

N is n

0 is first term - difference

first term is 3

diff is 6

3-6 = - 3

nth term is 6n-3

then, we just substitute which is n is the 36th term

: 6 (36) - 3 = 213