Question

8,40,200,...t10find the 4th term

Answer 1

We are asked to find the 4th term of the series above

The first term a = 8,

This is a geometric series because

The common ratio r is 5,

That is

`\begin{gathered} (200)/(40)=5 \\ (40)/(8)=5 \end{gathered}`

nth term of a geometric series is given by the formula

`T_n=ar^(n-1)`

The 4th term becomes

`\begin{gathered} T_n=ar^(n-1) \\ T_4=ar^(4-1) \\ T_4=ar^3 \\ T_4=8*5^3 \\ T_4=8*125 \\ T_4=1000 \end{gathered}`

Hence the 4th term is 1,000