Question

The sum of the first and third term of an A.P. is 12 and the product of first and second term is 24, the first term is

• A. 1
• B. 8
• C. 4
• D. 6

Answer 1

Answer: (C)

4

Answer 2

Let $a - d,a,a + d,........$ be an A.P.

∴ $(a - d) + (a + d) = 12 \Rightarrow a = 6$. Also, $(a - d)a = 24$

⇒ $6 - d = \frac{24}{6} = 4$ ⇒ $d = 2$

∴ First term$= a - d = 6 - 2 = 4$