Question

15,60, 240, fine the 6th term

Answer 1

Notice that the sequence has a common ratio of 4:

`\begin{gathered} 15*4=60 \\ 60*4=240 \end{gathered}`

The n-th term of a sequence with first term equal to a and common ratio r is:

`a\cdot r^(n-1)`

The first term of this sequence is 15 and the common ratio is 4, then the nth term is:

`15\cdot4^(n-1)`

Substitute n=6 to find the 6th term:

`15\cdot4^(6-1)=15\cdot4^5=15\cdot1024=15,360`

Therefore, the 6th term of the sequence, is:

`15,360`