Let's see if I've got it right (didn't look for other answers).
Turtle = x
Cat = y
Table = z
y + z - x = 170
z - y + x = 130
_ _ _ _ ... _ _ _ _
2 z = 300
z = 150 cm
Let's see if I've got it right (didn't look for other answers).
Turtle = x
Cat = y
Table = z
y + z - x = 170
z - y + x = 130
_ _ _ _ ... _ _ _ _
2 z = 300
z = 150 cm