Question

The 13 term of an arithmetic sequences 30. What is the sum of the 1 st and 25 th terms?

Answer 1

Here, a₁₃ = 30

a + 12d = 30

a = 30 - 12d

a₁ + a₂₅ = a + a + 24d

. = 2(30 - 12d) + 24d

. = 60 - 24d + 24d

. = 60

Hence, the sum of the first term and the twenty-fifth term is 60.