Question

15,60, 240, fine the 6th term

Answer 1

Notice that the sequence has a common ratio of 4:

$\begin{gathered} 15\times4=60 \\ 60\times4=240 \end{gathered}$

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:

$15,360$