Quoted from "--Arya--" 12 x 12 = 9 23 x 23 = 16 34 x 34 = ? Quoted from "--Arya--" Multiply 12*12=144 Sum of the digits of its product 1+4+4=9 Therefore 12*12=9 In the same way Multiply 23*23=529 Sum of the digits of its product 5+2+9=16 asnd now Multiply 34*34=1156 Sum of the digits of its product 1+1+5+6=13 Therefore 34*34=13 was a hard one