Question

If a_n denotes the nth term of the A.P. 3, 8, 13, 18, ..., then the value of a₃₀ – a₂₀ is ______.

Answer 1

If a_n denotes the nth term of the A.P. 3, 8, 13, 18, ..., then the value of a₃₀ – a₂₀ is 50.

Explanation:

The AP has first term a = 3 and common difference d = 5.

So a₃₀ – a₂₀ = (a + 29d) – (a + 19d)

= 10d 

= 10 × 5 

= 50