Question

Insert five numbers between 8 and 26 such that the resulting sequence is an A.P. 

Answer 1

Let required five numbers be x₁, x₂, x₃, x₄, x₅ 

∴ 8, x₁, x₂, x₃, x₄, x₅, 26 are in A.P. 

⇒ First term = 8 and seventh term = 26 

⇒ a = 8 and a + 6d - 26 

⇒ 3 = 8 and 6d = 26 – a = 26 – 8 = 18 

⇒ a = 8 and d = 3 

Hence x₁= a + d = 8 + 3 = 11 

x₂ = a + 2d = 8 + 6 = 14 

x₃ = 17, x₄ = 20, x₅ = 23