Question

The mean of the series $a , a + n d , a + 2 n d$ is.

• A. $a + ( n - 1 ) d$
• B. $a + n d$
• C. $a + ( n + 1 ) d$
• D. None of these

Answer 1

Answer: (B)

$a + n d$

Answer 2

Mean $= \frac { a + ( a + n d ) + ( a + 2 n d ) } { 3 }$

$= \frac { 3 a + 3 n d } { 3 } = a + n d$ .