Question

In a three digit number, the hundreds digit is twice the units digit. If the digits are reversed, the new number is 396 less than the original number. Find the number.

Answer 1

let the unit digit be x
then the hundred digit is 2x
let the tens digit by y

so the number is 100(2x) + 10y + x
= 201x + 10y

the number reversed is
100(x) + 10y + 2x
= 102x + 10y

201x+10y - (102x+10y) = 396
99x = 396
x = 4
looks like y can be any digit from 0 to 9

the original number could be
814, reverse = 418 , difference = 396
874, reverse = 478, difference = 396
etc

Answer 2

246