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By: T0116060A (offline)  Friday, August 23 2013 @ 07:58 PM CDT (Read 1339 times)  
T0116060A

Sulin shifted the decimal point of a number twice to the right to obtain a new number. The difference between the new number and the original number was 632.61.

(a) How many times of the new number is the original number?
(b) Find the sum of the two numbers and multiply it by 3.

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By: gerchan (offline)  Friday, August 23 2013 @ 09:48 PM CDT  
gerchan

Hi,
Below is my solution:

Take 100 - 61 = 39
39 will be my tenths and hundredths place.
Therefore, original number will be 6.39 and new number is 639
check: 639 - 6.39 = 632.61 (correct)

a) 100
b) 1936.17

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By: echeewh (offline)  Saturday, August 24 2013 @ 09:51 PM CDT  
echeewh

Hey <T0116060A>

Thank you , <gerchan>, for your solution , but I think the answer to (a) is (1/100) and not 100 as per your solution. That could be due to a misinterpretation of the question in (a).

Moreover, an Alternative worked solution is provided as follows:

(a)
Shifting the decimal point of a number twice to the right = Multiply number by 100 times.

New number = (Original number) × 100

Original number = (New number) ÷ 100

Hence, (1/100) times (New number) is the Original number.

(b)
Let Original number be 1u

Given that the difference between the new number and the original number was 632.61, we have ...

New number - Original number = 632.61
New number = 1u + 632.61 -- (1)

From (a),
New number = 100 × Original number = 100u -- (2)

Thus, (1) = (2)
1u + 632.61 = 100u
99u = 632.61
1u --> 6.39 {Original number}

Sum of (Original number) and (New number)
= 6.39 + 639
= 645.39

Multiply 3:
645.39 × 3 = 1936.17

=========

Trust this helps.

Do let me know again if this is different from your <Answerkey> or if there's further clarification.

Cheers,
Edward

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By: gerchan (offline)  Sunday, August 25 2013 @ 11:24 PM CDT  
gerchan

oh yes.. (a) answer should be 0.01 ...
sorry sorry...

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By: T0116060A (offline)  Monday, August 26 2013 @ 04:23 AM CDT  
T0116060A

But the answer key for (a) is 0.01 and for (b) is 645.39??? Eek!

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By: T0116060A (offline)  Monday, August 26 2013 @ 04:52 AM CDT  
T0116060A

But the answer key for (a) is 0.01 and for (b) is 645.39??? Eek!

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By: echeewh (offline)  Monday, August 26 2013 @ 07:43 AM CDT  
echeewh

Hi <T0116060A>

Thank you for your <Answerkey> and it is much appreciated if you can also provide this <Answerkey> from the start , whenever possible. We will then be able to verify this with our worked solutions too.

As for (a), (1/100) is the same as or equal to 0.01.

For (b), the <Answerkey> of 645.39 is part of the solution only that represents the sum of both numbers , i.e. (New Number) + (Original Number), as can be seen in both our worked solutions. But the question is this - Find the sum of the two numbers and multiply it by 3. We did accordingly, and hence, you have to do the following:

645.39 × 3 = 1936.17*

*There are occasions when typo errors and/or misprints and/or incomplete solutions are found in <Answerkey>.

Hope this clarifies.

Thank you and all the best,
Edward

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