Question 200248
Let the number be THDO. Where T is the thousands digit, H the hundreds, etc
Given
{{{T = D + 4}}} T<= 9
{{{D = 2*O}}}
{{{H = 1}}}

Since T is <= 9, then D must be <=5
D is 2*O, so D must be even. 
What are the even numbers less than 5? 0, 2, 4
Do D can be 0, 2 or 4
D = 2 * 0.
So O can be 0, 1 or 2

Possible numbers are
THDO
4100
6121
8142