Question

If the common difference of an A.P. is 5, then a₁₈ – a₁₃ = ______.

Answer 1

If the common difference of an A.P. is 5, then a₁₈ – a₁₃ = 25.

Explanation:

In an A.P., a_n = a + (n – 1)d.

So a₁₈ – a₁₃ = (18 – 13) × d = 5 × d. 

With d = 5, a₁₈ – a₁₃ = 5 × 5 = 25.