a) 2, 6, 18, 54, 162, 486
Explicatie: b1=2
b2=b1*q=2*3=6
b3=b1*q^2=2*9=18
b4=b1*q^3=2*27=54
b5=b1*q^4=2*81=162
b6=b1*q^5=2*243=486
Sau
b3=b2*q=6*3=18
b4=b3*q=18*3=54
b5=b4*q=54*3=162
b6=b5*q=162*3=486
Unde q este ratia in progresia geometrica
b) 4, 2, 1, 1/2, 1/4, 1/8
c) 3, 6, 12, 24, 48, 96
