Question

find the mystery number . The mystery number had two digits. The sum of the two digits is less than five teipple the mystery number and the result is the same as the product of 4x9

Answer 1

I believe your mystery number is 12.
12 has two digits.
The sum of the two digits, which is 3, is less than 5.
If you triple 12, you get 36 which is the same as the product of 4 multiplied by 9, which is also 36.