If thew first and sixth terms of geometric progessions are $$\frac{2}{3}$$ and 162 respectively then the $$8^{th}$$ term of the progression is
let the first term is a and common ratio is r then
$$T_{1}$$= {a}$$\times{r}^{1-1}$$ = a = $$\frac{2}{3}$$ equation 1
$$T_{6}$$= {a}$$\times{r}^{6-1}$$ = {a}$$\times{r}^{5}$$ = 162 equation 2
equation 1 \equation 2
$$\frac{2}{3}$$\162 = 1\r^5
243 = r^5
3 = r
r = 3
put the value of a and r in equation following equation
$$T_{8}$$= {a}$$\times{r}^{8-1}$$ = $$\frac{2}{3}$$ $$\times{3}^{7}$$
$$T_{8}$$ = $$\frac{2}{3}$$ $$\times243$$ $$\times3$$ $$\times3$$
$$T_{8}$$ = 1458 Answer
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