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#1 2006-10-12 03:47:54

Neha
Member
Registered: 2006-10-11
Posts: 173

sum

the sum of the digits of a two-digit counting number is 5.
when the digits are revversed , the number is27 greater than the original number.
what are the two numbers?


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#2 2006-10-12 03:53:16

luca-deltodesco
Member
Registered: 2006-05-05
Posts: 1,470

Re: sum

the possible numbers for condition a is

14
23
32
41
50

the only one that when reversed is 27 more, is 41, 41 reversed, is 14, 41-14 = 27

so youre answer is 41, and 14


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#3 2006-10-12 03:57:20

Neha
Member
Registered: 2006-10-11
Posts: 173

Re: sum

oh ok .
that wasnt that hard as i thought it was thanks


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#4 2006-10-12 10:05:01

pi man
Member
Registered: 2006-07-06
Posts: 251

Re: sum

Let's say your 2 digit number is XY which is 10X + Y.     You have 2 equations to work with:

X+Y=5  or X=5-Y
and
10X + Y = 10Y + X - 27 or 9X = 9Y - 27  or X = Y - 3

Substitute 5-Y for X in the 2nd equation:
5 - Y = Y - 3
8 = 2Y
Y = 4

Therefore X=1; your original is 14 and the reverse is 41.    Just as luca-deltodesco said.

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