Question

a=18.9 d=2.5 an=3.6 find n​

Answer 1

Step-by-step explanation:

Here, a=−18.9,d=2.5 and an=3.6.

Therefore, an=a+(n−1)d

−18.9+(n−1)×2.5=3.6

⇒(n−1)×2.5=22.5

⇒n−1=9

∴n=10