Question

Howmany terms are in the ap 6,3,0,-3....-36?

Answer 1

${\red{\bold{\text{Answer:-}}}}$

AP = 6,3,0,-3,........-36

a(first term) = 6

d(common difference)=a2-a1

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀=3-6

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀=-3

an(last term)=-36

${\text{\blue{We know that}}}$

$an=a+\left(n-1\right)d$

-36=6+(n-1)(-3)

-36-6=(n-1)(-3)

-42=(n-1)(-3)

$\frac{-42}{-3}$=n-1

14=n-1

14+1=n

15=n

⠀⠀

${\blue{\bold{\text{Hence there are 15 terms in AP}}}}$