Impreuna cei doi soferi au lucrat 98 de ore.
Folosim regula de trei simpla
98 ore..........58 l
50 ore............x l
x= (58·50)÷98 = 2900÷98 = 30 litri - primul sofer
98 ore..........58 l
48 ore...........y l
y=(48·58)÷98 = 2784÷98 = 28 litri - al doilea sofer