Answer :
What you have to do is add them all!
20 bar
11.4 2 11.4 weights
11.4
4.5 2 4.5 weights
4.5
450.0 4 450 weights
450.0
450.0
+450.0
---------
1.8
10
200
+1,600
--------------
1,811.8 is the answer
20 bar
11.4 2 11.4 weights
11.4
4.5 2 4.5 weights
4.5
450.0 4 450 weights
450.0
450.0
+450.0
---------
1.8
10
200
+1,600
--------------
1,811.8 is the answer