Question

The sum of the first 30 terms of the A.P. 1, 3, 5, 7, ... is:

• A. 900
• B. 990
• C. 890
• D. 800

Hint:

Use the formula \(S_n = \frac{n}{2} \left( 2a_1 + (n - 1) \cdot d \right)\) to find the sum of an A.P.

Answer 1

The Correct Option is A

The A.P. has \(a_1 = 1\) and \(d = 2\). The sum of the first \(n\) terms is: \[ S_n = \frac{n}{2} \left( 2a_1 + (n - 1) \cdot d \right) \] Substituting values for \(n = 30\), \(a_1 = 1\), and \(d = 2\): \[ S_{30} = 15 \times 60 = 900 \]