Question 1039058
A number round off to four thousand, 
If the digit in the hundred place is twice in the 10th place, the sum of the digit is 12 the number uses only 2 different digits.
 Find the number.
:
1000a + 100b + 10c + d is the number
"the digit in the hundred place is twice the 10s place"
b = 2c, (b and c are different)
:
How about 4422?