First of all, we know that the number has 3 digit, so we have this expression;
a00+b0+c where a00 represent hundreds, b0 represent tens, and c represent one
Or you can just have this abc instead of a00+b0+c
Next step:
the hundreds digit is four more than the ones digit. Translate this into the number which is:
a=4+c, or c=a-4
the tens digit is twice the hundreds digit, and translate this too which is:
b=2a
Lasly,
The sum of the digits is 12, also translate this:
a+b+c=12
c=a-4
b=2a
Substitute all this into a+b+c=12
a+2a+a-4=12
4a-4=12
Add 4 to each side
4a-4+4=12+4
4a=16
Divided 4 to both side
4a/4=16/4
a=4
b=2a
b=2(4)
b=8
c=a-4
c=4-4
c=0. As a result, the three digit is 480 which is your final answer. Hope it help!
