Respuesta :

I believe it would be 20.

Answer:

value of a3 = 20

Step-by-step explanation:

5, 10, 20, 40, 80...

We are given with a sequence of numbers

First  term is 5

second term is 10

third term is 20

fourth term is 40  and so on

first term is a1, second term is a2, third term is a3 , fourth term is a4  and so one

Here third term is a3 = 20