Question

If the 10th term of an A.P. is 21 and the sum of its first 10 term is 120‚ find its nth term.

Answer 1

Answer:

1+n

Step-by-step explanation:

s₁₀ = 10 (a+l) / 2

120= 5 (a+21)

24= a+21

a = 3

a₁₀ = a+(10 - 1)d

21 = 3+9d

18=9d

d=2

aₙ= a+ (n-1)d

  = 3+(n-1)2

  = 3-2+n

   = 1+n