The answer would be $56
The reason is you would do 80*.3(30% in decimal form) which would equal 24
24 is what is being taken off of the normal cost.
So you would then do 80-24 which would equal $56.
I think it's 138 Long by 109.5 more accurate .
92/73 = 1.26
120/100 = 1.2
138/109.5 =1.26
Hence 138 by 109.5 is more proportionate