Odpowiedź :
[tex]1 \ km=1000 \ m\rightarrow 1 \ m=\frac{1}{1000} \ km\\\\1 \ h=3600 \ s\rightarrow 1 \ s=\frac{1}{3600} \ h\\\\25 \ \frac{m}{s}=25\cdot\frac{\frac{1}{1000} \ km}{\frac{1}{3600} \ h}=25\cdot\frac{3600}{1000} \ \frac{km}{h}=25\cdot3,6 \ \frac{km}{h}=90 \ \frac{km}{h}[/tex]