The answer is 91
) `; R" t5 c/ z* h. x1 row 3x4+1x3=15tvb now,tvbnow,bttvb* ~6 \. r$ D+ i9 L: [8 |3 T: @" B
2 row 4x5+2x4=28
3 q# D \$ f7 `8 r- Aos.tvboxnow.com3 row 5x6+3x5=45
+ J3 u/ ?9 t2 |8 ^ T4 row 6x7+4x6=66
( ]0 ~7 M! w, X! Rtvb now,tvbnow,bttvb5 row 7x8+5x7=91  |