Respuesta :

ratio is the simpified fraction 
80/20 =4/1 or 4 
20/5=4/1 or 4

so the common ratio is 4

Please award me BRAINLIEST if my answer is satisfactory.
Thanks!
a₁ = 80;  a₂ = 20;  a₃ = 5...

common ratio = a₂/a₁ = 20/80 = 1/4
or
common ratio = a₃/a₂ = 5/20 = 1/4

Just divide a successive pair of terms

Answer: 1/4