Question

Which of the following lists of numbers form an A.P.? If they form an A.P., find the common difference d and write the next three terms : a, 2a, 3a, 4a,...

Answer 1

a, 2a, 3a, 4a,...
Here first term (a) = a
Common difference (d) = 2a – a = a
3a – 2a = a
4a – 3a = a
∵ The common difference is same
∴ It is an A.P.
and next three terms are
5a, 6a, 7a.