Question

7th term of an arithmetic sequence is 100 and 11th term is 140.
(ii) What is the third term of this sequence ?

Hint:

Once you know any term and the common difference, you can find any other term easily. Use the relation am = aₙ + (m-n)d. To find a₃ from a₇, calculate a₃ = a₇ + (3-7)d = 100 + (-4)(10) = 60. This avoids the need to find the first term, a.

Answer 1