Question 1022028
the sum of a geometric series is Sn = a(1 - r^n) / (1 - r) where a is the first term, r is the common ratio, and n is n consecutive terms
:
S10 = 10(1 - (1/2)^10) / ( 1 - (1/2))
:
S10 = 10(1 - (1/(2^10))) / (1/2)
:
divide by 1/2 means multiply by 2
S10 = 20(1 - (1 /2^10)
:
20 = 2^2 * 5
S10 = 20 - (((2^2)*5)/ 2^10)
:
S10 = 20 - (5 / 2^8)
:
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Answer is D
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