3*50     10                   4*75         16

4*50     10                  6*75          26

5*50     16                  8*75          45

6*50     16                  4*100         26

8*60     29.5                6*100        36

10*75    43                   8*100        49

12*75    59.5                10*100       71

14*100   120               12*100        91

16*100   175                18*100       205

20*100   235