Answer:
18 miles per hour
Step-by-step explanation:
Let x be the normal rowing speed with no wind,
∵ the wind added 5 miles per hour in the normal rate with wind and subtracted 5 miles per hour from normal rate against the wind,
⇒ Speed with the wind = ( x + 5 ) miles per hour,
While the speed against the wind = ( x - 5 ) miles per hour,
[tex]\because Time =\frac{distance}{speed}[/tex]
If the distance is 46 miles with wind,
Then, time taken = [tex]\frac{46}{x+5}[/tex] hours
While, if the distance is 26 miles against the wind,
Then, the time taken = [tex]\frac{26}{x-5}[/tex] hours,
According to the question,
[tex]\frac{46}{x+5}=\frac{26}{x-5}[/tex]
[tex]46(x-5)=26(x+5)[/tex]
[tex]46x-230=26x+130[/tex]
[tex]20x = 360[/tex]
[tex]\implies x = 18[/tex]
Hence, the normal rowing speed is 18 miles per hour