The answer is 91公仔箱論壇0 j1 S3 _# c2 t4 P! A% c+ V7 o
1 row 3x4+1x3=15
6 Q/ n: P/ c% w2 row 4x5+2x4=28os.tvboxnow.com2 Y; a. i P: l5 n' R3 d, e# p
3 row 5x6+3x5=45
3 ]9 O; {/ o; u$ O3 S# z' \8 B: jtvb now,tvbnow,bttvb4 row 6x7+4x6=66
G/ [; |' n) k; A* x4 btvb now,tvbnow,bttvb5 row 7x8+5x7=91  |