Answers

2015-01-12T20:33:48+08:00
Let x be the tens digit
2x for ones digit

x+2x=9
3x=9
 
Divide both sides by 3 the answer is:
x=3

The number is 36

Proof:
x=3
2x=6
Adding them gives us 9
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2015-01-12T21:28:28+08:00
The answer is 63
Because : 
The sum of my digit is 9 : 6 + 3 = 9
My ones digit is twice my tens digit : 3 x 2 = 6
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