1 |----------|
2 |----------|----------|
3 |----------|----------|----------|----------|
4 |----------|----------|----------|----------|----------|----------|-----------|----------| } 1650
1650 : 15 = 110 km ( in prima zi)
110 × 2 = 220 km ( in a doua zi)
220 × 2 = 440 km ( a treia zi)
440 × 2 = 880 km ( a patra zi).
Verificare: 110 + 220 + 440 + 880 = 1650 km ( 1+2+3+4).