Răspuns:
a+b+c=685
a|.........|
b|.........|...|36
c|. .. .. |...[36]......|58
egalam segmentele
685-36-36-58=555
aflam cati litri se afla in primul butoi:
555:3=185 litri
aflam cati litri sunt in al doilea butoi
185+36=221litri
aflam cati litri sunt in al treilea butoi
221+58=279litri
v:185+221+279=685 litri