2+2+2^2+2^3+2^4+2^5+2^6+2^7+2^8
2+2 = 2^2
2^2 + 2^2 = 2*2^2 = 2^3
2^3 + 2^3 = 2*2^3 = 2^4
and so on
2^8 + 2^8 = 2^9 = 512
Does help if you put the options.
expressions
This topic has expert replies
Source: Beat The GMAT — Problem Solving |
logitech gave a very good solution for this
2+2+2^2+2^3+2^4+2^5+2^6+2^7+2^8 = A
Multiply both sides by 2
2^2+2^2+2^3+2^4+2^5+2^6+2^7+2^8 + 2^9 = 2A
2+2+2^2+2^3+2^4+2^5+2^6+2^7+2^8 + 2^9 = 2A
A + 2^9 = 2A
A = 2^9
2+2+2^2+2^3+2^4+2^5+2^6+2^7+2^8 = A
Multiply both sides by 2
2^2+2^2+2^3+2^4+2^5+2^6+2^7+2^8 + 2^9 = 2A
2+2+2^2+2^3+2^4+2^5+2^6+2^7+2^8 + 2^9 = 2A
A + 2^9 = 2A
A = 2^9
SACX

















