Sign in
Please select an account to continue using cracku.in
↓ →
What is the sum of the first 9 terms of an arithmetic progression if the first term is 7 and last term is 55?
$$S_{n} = \frac{n}{2}(a+l)$$
$$S_{9} = \frac{9}{2}(7+55) = 279$$
So the answer is option D.
Create a FREE account and get: