Sophie's favorite number is a two-digit number. If she reverses the digits, the result is 36 less than her favorite number. Also, one digit is 3 more than double the other digit. What is Sophie's favorite number?
Sophie's favorite number is 85.
[10a + b] - [10b + a] ==36,
a=2b + 3, solve for a, b
Use substitution to get:
a =5 and b=1
And Sophie's favorite numbers is: 51
