Question

If 2 + 2^2 + 2^3 +...+ 2^n = 510 then n = ?

Answer 1

Answer:

N= 8

Step-by-step explanation:

Answer 2

Answer:

n = 8

Step-by-step explanation:

This Geometric series. r = 2 and a = 2

$S_{n}= \dfrac{a(r^{n}-1)}{r-1}\\\\\\\dfrac{2(2^{n}-1)}{2-1}=510\\\\\dfrac{2*(2^{n}-1)}{1}=510\\\\2*(2^{n}-1) = 510\\\\2^{n-1}=\dfrac{510}{2}\\\\2^{n} - 1 = 255\\\\2^{n}=255+1\\\\2^{n} = 256\\\\2^{n} =2^{8}$

n = 8