To find the mile per hour rate equivalent to 40 km per hour, let's convert 40km to miles using the given equivalence in the question.
[tex]\begin{gathered} 1.6\operatorname{km}=1mi \\ 40\operatorname{km}\times\frac{1mi}{1.6\operatorname{km}}=\frac{40\operatorname{km}mi}{1.6\operatorname{km}}=25mi \end{gathered}[/tex]Therefore, 40 km = 25 miles.
The mile per hour rate equivalent to 40km per hour is 25 miles per hour.