Question

i am a 3digit number that is less than 500. My ones digit is twice the hundreds digit. The sum of the three digits is 14. What number am I?

Answer 1

the three possible answers are 428, 356, and 284. All are less than 500, all have a units digit twice the hundreds digit, and all have 14 as a sum of digits.

Answer 2

ooh fun

so xyz=number
z=2x
x+y+z=14
subsitute z=2x into x+y+z=14
x+y+(2x)=14
3x+y=14
number must be 3 digit and less thaan 500
since the tens digit's max is 9 then
z+x≥14-9
z=2x
3x≥5
x max=5 because 500 is max so 
x could be 2,3,4 so 

284
356
428
are the numbers