6 / 7 = 42 =>2 3 / 9 = 27 => 7 8 / 2 = 16 => 6

Then

4 / 5 = 20 =>0

Answer is 0.

Approach - multiply both the number and take first digit.

6*7 = 42 -> 2 3*9 = 27 -> 7 8*2 = 16 -> 6 similarly 4*5 = 20 -> 0

If

3 2 = 7 5 4 = 23 7 6 = 47 9 8 = 79

10 9 = ??

If 9+5+6=454854 8+4+2=328316 5+9+3=452515 Then 9+4+7=?