4 Digit Number That Has Twice As Many Thousands As Ones, Twice As Many Ones As Hundreds, And Twice As Many Hundreds As Tens?

Thousands place = 1000 (2 x Ones place)
Ones place = 1 x (2 x Hundreds place)
Hundreds place = 100 x (2 x Tens place)
Putting all in terms of ones:
Let x = ones place
x/4 = tens place
x/2 = hundreds place
2x = thousands place

1000 * (2x) + 100 * (x/2) + 10 * (x/4) + 1 *( x) < 10,000
2000x + 50x + 5x/2 + x < 10,000
Multiply both sides by 2
4000x + 100x + 5x + x < 20,000
4106x < 20,000
x < 4.871
Since all place holders are integers, x = 4
Substitute the x value for the given above to return all other place holders
x/4 = 4/4 = 1
x/2 = 4/2 = 2
2x = 2*4 = 8
ones place = 4
tens place = 1
hundreds place = 2
thousands place = 8
The 4 digit number is 8,214