Respuesta :
Answer:
15 mph
Step-by-step explanation:
Speed of wind = [tex]V_w[/tex] = 4 mph
Speed of Jaime rowing = [tex]V_r[/tex]
Speed of boat against wind = [tex]V_r-4[/tex].
Speed of boat with wind = [tex]V_r+4[/tex]
Time taken with and against wind is same = t
Distance travelled with wind = 57 mph
Distance travelled against wind = 33 mph
[tex]time=\frac{\text{Distance}}{\text{Speed}}[/tex]
Time taken to go with wind
[tex]t=\frac{57}{V_r+4}[/tex]
Time taken to go against wind
[tex]t=\frac{33}{V_r-4}[/tex]
So,
[tex]t=\frac{57}{V_r+4}=\frac{33}{V_r-4}\\\Rightarrow \frac{57}{33}=\frac{V_r+4}{V_r-4}\\\Rightarrow 57V_r-33V_r-228-132=0\\\Rightarrow V_r=\frac{360}{24}\\\Rightarrow V_r=15\ mph[/tex]
ā“ Her normal rowing speed with no wind is 15 mph