Question

Find the sum of first 51term of an AP whose second and third term are 14 and 18 respectively​

Answer 1

Explanation:

a₂ = 14

a₃ = 18

d = a₃ -a₂ = 18 - 14 = 4

a₁ = 14 - 4 = 10

nth term = a + (n-1)d

a₅₁ = 10 + 50 * 4

= 10 + 200

= 210