Answer:
Sali's speed was 18.75 km/h.
Step-by-step explanation:
Jane took 3.5 hours to cycle the 63 km.
As, [tex]Speed= \frac{Distance}{Time}[/tex] , so the speed of Jane will be: [tex]\frac{63}{3.5} km/h = 18 km/h[/tex]
Suppose, the speed of Sali is [tex]x[/tex] km/h
Sali caught up with Jane when they had both cycled 30 km.
So, the time required for Jane to cycle 30 km [tex]= \frac{30}{18}=\frac{5}{3} hours[/tex] and the time required for Sali to cycle 30 km [tex]=\frac{30}{x} hours[/tex]
Given that, Sali started to cycle 4 minutes or [tex](\frac{4}{60}) or (\frac{1}{15}) hours[/tex] after Jane started to cycle. So, the equation will be.......
[tex]\frac{5}{3}-\frac{30}{x}= \frac{1}{15}\\ \\ \frac{30}{x}= \frac{5}{3}-\frac{1}{15}\\ \\ \frac{30}{x}= \frac{24}{15}\\ \\ 24x=450\\ \\ x= \frac{450}{24}= 18.75[/tex]
Thus, the speed of Sali was 18.75 km/h.
