Question

Question #16a2c

Answer 1

3rd term is 20

Explanation:

This is called a geometric sequence, these have the genral nth term foruma of:

`a_n = a * r^(n-1)`

Where `a - "first term " n = 1`

`r = "common ration" = a_2 / a_1 = a_m / a_(m-1)`

Hence the first term of this is `a = 5`

and the ratio is `10/5 = 2`

So the nth term of this sequance is `5 * 2^(n-1)`

Applying this formula : `a_3 = 5 * 2^2 = color(red)(20`

or just looking at the sequence, `color(red)(20)` is the 3rd