Question

Quantos termos tem a P.G (2, 8, ... 2048)

Answer 1

an=2048
a1=2
q=4
n=?

an=a1.q(elevado ao n-1)
2048=2.4(n-1)
4(n-1)=2048-2
4n-1=2046
2046:4=n-1
511=n-1
n=511+1
n=512