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nfa1rhp
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In the series (1,2,4,8,16,32.....) what is the combined 21 Jul 2007, 11:15
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In the series (1,2,4,8,16,32.....) what is the combined value of the 16th, 17th, and 18th terms?

A. 4 (2^16)
B. 7 (2^15)
C. 5 (2^16)
D. 3 (2^16) + 2(2^15)
E. 6 (2^15)

I know the answer but I do NOT understand the breakdown of why. :shock:



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smily_buddy
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In the series (1,2,4,8,16,32.....) what is the combined 21 Jul 2007, 11:24
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nfa1rhp
In the series (1,2,4,8,16,32.....) what is the combined value of the 16th, 17th, and 18th terms?

A. 4 (2^16)
B. 7 (2^15)
C. 5 (2^16)
D. 3 (2^16) + 2(2^15)
E. 6 (2^15)

I know the answer but I do NOT understand the breakdown of why. :shock:
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16th term = 2^15
17th term = 2^16
18th term = 2^17

Adding them and taking 2^15 common we get 2^15(1+2+4)= 7(2^15)..thus B.
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nfa1rhp
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In the series (1,2,4,8,16,32.....) what is the combined 21 Jul 2007, 12:28
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smily_buddy
nfa1rhp
In the series (1,2,4,8,16,32.....) what is the combined value of the 16th, 17th, and 18th terms?

A. 4 (2^16)
B. 7 (2^15)
C. 5 (2^16)
D. 3 (2^16) + 2(2^15)
E. 6 (2^15)

I know the answer but I do NOT understand the breakdown of why. :shock:

16th term = 2^15
17th term = 2^16
18th term = 2^17

Adding them and taking 2^15 common we get 2^15(1+2+4)= 7(2^15)..thus B.
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That is the correct answer, but I'm not understanding where the 1 + 2 + 4 comes from. Thanks.
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ggarr
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In the series (1,2,4,8,16,32.....) what is the combined 21 Jul 2007, 15:37
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Quote:
Adding them and taking 2^15 common we get > 2^15+2^16 + 2^17 -> 2^15(1+2^1+2^2) -> 2^15(1+2+4)= 7(2^15)..thus B.
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Smily_buddy,

Can you redo this in a less terse fashion?
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anonymousegmat
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In the series (1,2,4,8,16,32.....) what is the combined 21 Jul 2007, 17:05
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ggarr
Quote:
Adding them and taking 2^15 common we get > 2^15+2^16 + 2^17 -> 2^15(1+2^1+2^2) -> 2^15(1+2+4)= 7(2^15)..thus B.
Smily_buddy,

Can you redo this in a less terse fashion?
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he is factoring out what is common in the the three terms, 2^15

2^15(1+2^1+2^2)
2^15(1+2+4)
7*2^15



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Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Quantitative Questions Forum
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Thank you for understanding, and happy exploring!