Question 551139
let the number = xy
The tens digit of a certain two digit number is two more than the units digit.
so,x=y+2
 The original number is 18 more than the number formed by interchanging the digits. 
xy=yx+18
from this we can understand that x,y values must be even numbers and x value is greater than y value.
take y=2,so x=2+2=4 (because no odd numbers)
xy=42
check xy=yx+18
=>42=24+18
=>42=42 satisfies the equations
so the original number is 42.