Onderon Palace Number Puzzle

To enter the storeroom in Onderon Palace (your second visit to Onderon), you must first answer some riddles. Here are the answers:

Riddle Answer
Twice first key number exceeds value of its half by 99 66
Reversing second key's digits increases value by 1/5 45
Third key differs from the reverse of its digits by twice the product of its digits 39