If LOCKER = 17 and TRAGEDY = 20. Then PREPLANING = ?

If LOCKER = 17 and TRAGEDY = 20. Then PREPLANING = ?

Explanation

LOCKER (6 letters) 6×3 =18 -1 = 17

 

TRAGEDY (seven letters) 7×3 =21 - 1 = 20.

 

PREPLANING (Ten Letters) 10 × 3 = 30 -1 = 29