Răspuns :
a+b+c=420
a=2c
c=b/7 => b = 7c
2c + 7c + c = 420
10c = 420
c = 42
b = 294
a = 84
a=2c
c=b/7 => b = 7c
2c + 7c + c = 420
10c = 420
c = 42
b = 294
a = 84
Răspuns:
a+b+c=420
a=2c
c=b/7 >b=7c
2c+7c+c=420
10c=420=>c=42 km parcurge in a3a etapa
b=7×42=>b=294 km parcurge in a2a etapa
a=2×42=>a=84 km parcurge in prima etapa