Question

The fifth term of a geometric progression is $81$, and the terms is $24$: then the ratio of fourth to first terms of progression is

• A. ${\left(\frac{3}{2}\right)}^3$
• B. ${\left(\frac{3}{2}\right)}^2$
• C. $\left(\frac{3}{2}\right)$
• D. $Noneofthese$

Answer 1

The correct option is A ${\left(\frac{3}{2}\right)}^3$

$\begin{array}{c}5thterma{r}^4=81\\ ar=24\\ r^3=\frac{81}{24}=1.5\\ \frac{4th}{1st}=\frac{a{r}^3}{a}={\left(\frac{3}{2}\right)}^3\end{array}$