Answer:
a_3=4
Explanation:
a1 = 100
r = 1/5
an = 100 (1/5)^(n - 1)
so we now have the answer for a_3
a_3 = 100 * (1/5)^(3 - 1)
a_3 = 100 * (1/5)^2
a_3 = 100 * 1/25
a_3 = 4
i believe this is it, although i'm not entirely sure
good luck :)
**please let me know if this was wrong/not what you were looking for or both**
have a nice day!