$900, but not too sure if this is a question to trick you.
For the second work sheet:
5 2/8 - 4 1/4= 1 so NO
8 3/4 - 7 1/2= 1 1/4 so YES
2 1/8 - 1 7/8= 1/4 so NO
9 5/12 - 8 1/6= 1 1/4 so YES
Sorry if its not enough explanation, hope it helps!
336473894875785686598685965867 - 67843993 = 3*10^29
The ratio of areas is the square of the scale factor, so that factor is
√(320/180) = 4/3