Question

Find the number of terms in each of the following AP's,:7,13,19,.....,205

Answer 1

Hi there !!

AP is 7,13,19,.....,205

a= First term

First term d=common difference

a2-a1=13-7=>6

an= last term

By using formula,

an=a+(n-1)d

205 =7+(n-1)6

205=7+6n-6

205-7+6=6n

204/6=n

34=n

The number of terms are 34

Thankyou :)

Answer 2

Answer :-

a = 7

d = 13 – 7 = 6

An = 205

An = a + (n–1) d

205 = 7 + (n–1) 6

205 – 7 = (n–1) 6

198 = (n–1) 6

n–1 = 198 / 6

n–1 = 33

n = 33 + 1

n = 34