Question 208260
You have a four digit number where the thousands digit is four greater than the hundreds digit. 
The tens digit is twice the thousands digit.
 The ones digit is half of the thousands digit.
 What is the number?
:
The 4 digit number: 1000a + 100b + 10c + d
:
"the thousands digit is four greater than the hundreds digit."
a = b + 4
or
b = a - 4 means a => 4
:
" The tens digit is twice the thousands digit." means a < 5
c = 2a
:
" The ones digit is half of the thousands digit." means a is an even number
d = .5a
:
 What is the number?
:
From the given information we conclude that a = 4, b = 0, c = 8, d = 2
:
Our number: 4082