b00 x 8 +a0 x 8= 1920
= b x 10 x10 x 8 + a x10 x 8 = 1920
= b0 x 80 + a x 80 = 1920
= 80 x( b0 + a) = 1920
= b0 +a = 1920 : 80 = 24
= b0 + a = 20 + 4 =24
=> b= 2
b00 x 8 + a0 x 8 = 1920
b x 10 x 10 x 8 + a x 10 x 8 = 1920
b0 x 80 + a x 80 = 1920
80 x ( b0 + a ) = 1920
b0 + a = 1920 : 80 = 24
b0 + a = 20 + 4 = 24
\(\Rightarrow\)b = 2