Number Series Puzzle

Mathematical Problem

Mathematical Problem for Entrance Test

If

6 / 7 = 2

3 / 9 = 7

8 / 2 = 6

Then

4 / 5 = ?

The answer is 0.
As
6 / 7 => 6x4 = 42 but the answer is written as 2
3 / 9 => 3x9 = 27 but the answer is written as 7
8 / 2 => 8x2 = 16 but the answer is written as 6
If we look at the answers, the second digit has been used in the problem.
Now, as
4 / 5 => 4x5 = 20 and the second digit is 0, the answer is 0.