Question

hi guys please solve this question​

Answer 1

Answer:

81

Step-by-step explanation:

Let the series be

$\frac{a}{ {r}^{3} } , \frac{a}{ {r}^{2} } , \frac{a}{r} , \: a ,\: ar ,\: a {r}^{2}, a {r}^{3} ,a {r}^{4}.$

So the 4th term a = 3

Given product of 3rd and 8th term is 243

$\frac{a}{r} \times a {r}^{4} = 243$

${a}^{2} {r}^{3} = 243 \\ a {r}^{3} = \frac{243}{a} \\ a {r}^{3} = \frac{243}{3} = 81$

7th term = ar^3 = 81

Hope you understand, if you've any doubts comment below ;))