A----------------------------------------------------------------------------------------------B
A------prima zi=18 km------C-------------------------------------D----------------------B
C a 2-a zi= 3/5 (AB-18KM) a 3-a z-=1/4 AB
Scriem AB =SUMA CELOR 3 ZILE AB= 18 +3/5(AB-18) +1/4AB aducem la acelasi numitor 20AB=20X18 +12(AB-18) +5AB ⇒AB=48 VERIFICARE
48=18 +3/5(48-18)+1/4(48)=18+18+12 ADEVARAT