1.  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 ?
A. 29
B. 70
C. 92
D. Cannot be determined
E. None of these

Answer: Option D

Explanation:

Let the ten's digit be x and unit's digit be y.
Then, (10x + y) - (10y + x) = 63
<=> 9(x - y) = 63
<=> x - y = 7.
Thus, none of the numbers can be determined.