Question

Find the $n^{th}$ term and the $7^{th}$ term of $3,-6,+12,-24$, ......

• A. $191$
• B. $193$
• C. $192$
• D. $194$

Answer 1

The correct option is C $192$

Given 3, -6, +12, -24,.....
$a=3,r=\frac{-6}{3}=-2$
$t_n={ar}^{n-1}={3(-2)}^{n-1}$
$\therefore t_7={3(-2)}^{7-1}=3\times {(-2)}^6=192$