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\(4 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7\)

= \(2^2 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7\)

= \(2^2(1 + 1 + 2 + 2^2 + 2^3 + 2^4 + 2^5)\)

= \(2^2(1 + 1 + 2 + 4 + 8 + 16 + 32)\)

= \(2^2*64\) = \(2^2*2^6\) = \(2^{2+6}\) = \(2^{8}\) (Option B)
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Bunuel
\(4 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7 =\)


A. 2^7

B. 2^8

C. 2^16

D. 2^28

E. 2^29

\(4 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7 =\)

Or ,\(2^2 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7 =\)

Or, \(2^2 ( 1 + 1 + 2 + 2^2 + 2^3 + 2^4 + 2^5) =\)

Or, \(4 ( 4 + 4 + 8 + 16 + 32) =\)

Or, \(4*64 =\)

Or, \(2^2*2^6=\)

Or, \(2^8=\)

Thus, answer will be (B)
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Bunuel
\(4 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7 =\)


A. 2^7

B. 2^8

C. 2^16

D. 2^28

E. 2^29

2^2 ( 1+1+2+2^2 + 2^3+ 2^4 + 2^5)
= " ( 2+2+2^2 +2^3+ 2^4 + 2^5)
= " (2^2 + 2^2 +2^3+2^4 + 2^5)
=" (16+16+32)
= 2^2 * 64
=2^2 * 2*6
= 2^8 (Exponent rule)
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Bunuel
\(4 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7 =\)


A. 2^7

B. 2^8

C. 2^16

D. 2^28

E. 2^29

\(4 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7 =\)
Rewriting as;
\(2+2 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7\)

\(2+2^1 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7\), Now it will be a Geomatric Progression

Sum of Geometric Progression \(=\frac{a(r^{n}-1)}{r-1}\) [a is the first term and r is the common ratio]

\(2+\frac{2(2^7-1)}{2-1}\)

\(=2+\frac{2(2^7-1)}{1}\)

\(=2+2^8-2\)

\(=2^8\)

The answer is B
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