Răspuns:
Explicație pas cu pas:
D = lungimea drumului
prima etapă D/4
rest D - D/4 = 4D/4 - D/4 = 3D/4
a doua etapă 1/4*3D/4 = 3D/16
rest (a treia etapă) 3D/4 - 3D/16 = 12D/16 - 3D/16 = 9D/16
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9D/16 = D/4 + 3D/16 + 150
9D/16 - D/4 - 3D/16 = 150
9D/16 - 4D/16 - 3D/16 = 150
2D/16 = 150
D/8 = 150
D = 150*8 = 1200 km