Carl is trying to find a combination. It's written in a riddle. Find 2/3 of the final number, add 16, and this number will equal two times the mystery number. What was the final number of the combination?

Answer 1

let the "mystery number" be x
Now just translate the English into math:

"Find 2/3 of the final number, add 16, and this number will equal two times the mystery number" ------>

(2/3)x + 16 = 2x

solve this little equation to get x=12