Two out of four can be represented as:
2/4
OR
1/2
The slope of diagonal PS is 4/4.
The slope diagonal QR is 4/4.
The midpoint of PS is 2/2.
The midpoint of QR is 2/2.
The last answer I believe is equal.
There are 56 dogs
2/5 = x/140
140 x 2 = 5 x x
280 = 5x
56 = x