rheam25 wrote:
\(3^7[\)(\(3^{−4}\)+\(3^{−5}\))+(\(3^{−5}\)+\(3^{−6}\))+(\(3^{−6}\)+\(3^{−7}\)) –\(3^{−7}\) ] is what multiple of 17?
A) 1
B) 2
C) 3
D) 4
E) 11
Take: \(3^7[\)(\(3^{−4}\)+\(3^{−5}\))+(\(3^{−5}\)+\(3^{−6}\))+(\(3^{−6}\)+\(3^{−7}\)) –\(3^{−7}\) ]
Expand to get: \(3^3 + 3^2 + 3^2 + 3^1 + 3^1 + 1 - 1\)
Evaluate: \(27 + 9 + 9 + 3 + 3 + 1 - 1\)
Evaluate: \(51\)
Since \(51 = (3)(17)\), the correct answer is C
Cheers,
Brent
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Brent Hanneson – Creator of gmatprepnow.com
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