a bar over a sequence of digits in a decimal indicates that the sequence repeats indefinitely.
what is the the value of (10^4-10^2) (.0012)? "bar of 12"
I got (10000-100)(.0012)=11.7800 closest answer was E. HA HA but there has to be easier way..cheers
a. 0
b..12 Bar over 12
c.1.2
d.10
e.12
I think there is a way of heavy division and multiplication that can make this much easier than my approach. I got the answer right but is there an easier way for this.
QA is E
og math 137..heavy division
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- Neo2000
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In your approach, you've neglected the bar which is incorrect.Enginpasa1 wrote:a bar over a sequence of digits in a decimal indicates that the sequence repeats indefinitely.
what is the the value of (10^4-10^2) (.0012)? "bar of 12"
I got (10000-100)(.0012)=11.7800 closest answer was E. HA HA but there has to be easier way..cheers
QA is E
Instead
(10^4-10^2) (.0012)? "bar of 12"
Take 10^2 common you get
10^2(10^2-1) (.0012)? "bar of 12"
Which gives you
(10^2-1) (.12)? "bar of 12"
which is
[100-1] (.12)? "bar of 12"
which equals
12.12"bar of 12" - (.12)"bar of 12"
which is Exactly = 12
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When the answer choices are spread out, estimation is a great way to answer questions
(10000 - 100) is pretty close to 10000.
10000 * (.00121212121212...) = 12.12121212...
pick (e) 12
(10000 - 100) is pretty close to 10000.
10000 * (.00121212121212...) = 12.12121212...
pick (e) 12
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Guys, my approach was similar to the OG's but I think there is a typo there or I need to take a break.
(10^4 - 10^2)(0.0012 bar)
10^4 (0.0012 bar) - 10^2 (0.0012 bar)
10000 (0.0012 bar) - 100 (0.0012 bar)
12 - 0.12= 11.88 ..
10^4 times 0.0012 should moves the decimal 4 places to the right, so what is my mistake?
(10^4 - 10^2)(0.0012 bar)
10^4 (0.0012 bar) - 10^2 (0.0012 bar)
10000 (0.0012 bar) - 100 (0.0012 bar)
12 - 0.12= 11.88 ..
10^4 times 0.0012 should moves the decimal 4 places to the right, so what is my mistake?
Abdulla
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Your mistake is that you're ignoring the repeating decimal.Abdulla wrote:Guys, my approach was similar to the OG's but I think there is a typo there or I need to take a break.
(10^4 - 10^2)(0.0012 bar)
10^4 (0.0012 bar) - 10^2 (0.0012 bar)
10000 (0.0012 bar) - 100 (0.0012 bar)
12 - 0.12= 11.88 ..
10^4 times 0.0012 should moves the decimal 4 places to the right, so what is my mistake?
10000(.0012 bar) = 12.12(bar), not 12.
Similarly, 100(.0012bar) = .12(bar), not .12
So, we end up with:
12.1212121212121212... - .1212121212121212... = 12
![Image](https://i.imgur.com/YCxbQ7s.png)
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Here is a little trick ya can pull off.
0.111.. = 1/9
0.121212.. = 12/99
0.123123123... = 123/999
0.030303.. = 03/99
0.0121212.. = 012/990
0.00121212.. = 0012/9900
10^4 - 10^2 = 9900
Look at the last fraction, the denominator is 9900, look at the 0's on numerator as well as on denominators side as well.
0.111.. = 1/9
0.121212.. = 12/99
0.123123123... = 123/999
0.030303.. = 03/99
0.0121212.. = 012/990
0.00121212.. = 0012/9900
10^4 - 10^2 = 9900
Look at the last fraction, the denominator is 9900, look at the 0's on numerator as well as on denominators side as well.