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How many zeros will the decimal equivalent of
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30 Jul 2017, 08:27
30 Jul 2017, 08:27
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Question Stats:
43% (01:58) correct
56% (01:32) wrong based on 134 sessions
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How many zeros will the decimal equivalent of \(\frac{1}{2^{11} * 5^7}+\frac{1}{2^7 *5^{11}}\) have after the decimal point prior to the first non-zero digit?
(A) 6
(B) 7
(C) 8
(D) 11
(E) 18
Re: How many zeros will the decimal equivalent of
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22 Sep 2017, 20:32
22 Sep 2017, 20:32
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Carcass wrote:
How many zeros will the decimal equivalent of 1/{2^(11) * 5^(7)} + 1/{2^(7) *5^(11)} have after the decimal point prior to the first non-zero digit?
(A) 6
(B) 7
(C) 8
(D) 11
(E) 18
(A) 6
(B) 7
(C) 8
(D) 11
(E) 18
There is graphical representation error, even I read incorrectly i read as 1/2^1 * 15^7 but it is 1/{(2^11) * (5^7)} .Hope it helps
Now comming back to question to make the decimal terminating we have to bring the decimal in the form \(2^n * 5^n\)
From the equation \(\frac{1}{2^{11} * 5^7}+ \frac{1}{2^7 * 5^{11}}\)
We take\(\frac{1}{(2^7 * 5^7)} * [\frac{1}{(2^4)} + \frac{1}{(5^4)}]\)
= \(\frac{1}{10^7}\) \([\frac{1}{16}\) + \(\frac{1}{625}]\)
= \(\frac{1}{10^7}\) \([\frac{641}{10^4}]\)
= \(\frac{641}{10^{11}}\)
= 8 decimal point ( since 641 >100)
General Discussion
Re: How many zeros will the decimal equivalent of
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19 Sep 2017, 09:26
19 Sep 2017, 09:26
Any help here? I tried using the properties of exponential but I am completely stuck!
