Odpowiedź:
1 km=1000m
1m=100cm
1h=60min
1min=60s
[tex]150min=150*\frac{1}{60}h=2,5h\\\\3,5h=3,5*60min= 210min\\\\30\frac{cm}{min}=30\frac{0,01m}{60s}=0,005\frac{m}{s}\\\\50\frac{m}{s}=50*\frac{0,001km}{\frac{1}{60}h }=50*0,001*\frac{60}{1}\frac{km}{h}=3\frac{km}{h}[/tex]