The difference between a two-digit number and the number obtained by interchanging the positions of its digits is 36. What is the difference between the two digits of that number?  Pick:
A) 1
B) 2
C) 3
D) 4
E) None
Let the ten's digit be x and unit's digit be y.   Then, (10x + y) - (10y + x) = 36   9(x - y) = 36   x - y = 4.   Option 4
<result>D</result>
The difference between a two-digit number and the number obtained by interchanging the positions of its digits is 36. What is the difference between the two digits of that number?