The difference between a two-digit number and the number obtained by interchanging the two digits is 63. Which is the smaller of the two numbers ? Select:
A) 3 B) 6 C) 5 D) 7 E) 9
Explanation:   Let the ten's digit be x and unit's digit be y.   Then, (10x + y) - (10y + x) = 63   =&gt; 9 (x - y) = 63   =&gt; x - y = 7.   Thus, none of the numbers can be deermined..   Answer: 7
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The difference between a two-digit number and the number obtained by interchanging the two digits is 63. Which is the smaller of the two numbers ?