Exponents

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Exponents

by adi » Fri Mar 14, 2008 7:44 pm
2 + 2 + (2^2) + (2^3) + (2^4) + (2^5) + (2^6) + (2^7) + (2^8) =

A) 2^9
B) 2^10
C) 2^16
D) 2^35
E) 2^37

The answer should be A.
Source: — Problem Solving |

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by simplyjat » Fri Mar 14, 2008 10:42 pm
This is a type of question where you have to find out the pattern...

2 + 2 = 4 = 2^2
4 + 2^2 = 8 = 2^3
8 + 2^3 = 16 = 2^4
16 + 2^4 = 32 = 2^5
....

Also you can think like this
2^1 + 2^1 = 2^1(1+1) = 2.2^1 = 2^2
2^2 + 2^2 = 2^2(1+1) = 2.2^2 = 2^3
2^3 + 2^3 = 2^3(1+1) = 2.2^3 = 2^4
2^4 + 2^4 = 2^4(1+1) = 2.2^4 = 2^5
simplyjat