Răspuns :
a) Fie X lungimea totala a drumului.
In prima zi parcurge: 20% * X = 0.2X
In a doua zi parcurge: 0.2X + 25% * 0.2X = 0.2X + 0.25*0.2X = 0.2X + 0.05X = 0.25X
In a treia zi parcurge: 330 km
Obtinem urmatoarea ecuatie:
0.2X + 0.25X + 330 = X
0.45X + 330 = X
330 = X - 0.45X
330 = 0.55X
X = 330/0.55 = 600 km.
b)
In a doua zi a parcurs 0.25 X, adica 0.25 * 600 = 150 km.