lets see who is intelligent....

[Shahid Geo]

[Papu]

9=72 90 - (9+9) = 72
8=56 72 - (8+8) = 56
7=42 56 - (7+7) = 42
6=30 42 - (6+6) = 30
5=20 30 - (5+5) = 20
3=? 20 - (3+3) = 14

3=3. answer ..........

[suleman84]

9*8=72
8*7=56
7*6=42
6*5=30
5*4=20
4*3=12
3*2=6