Given:-
Callie walked 14.5 km. And also given 8 km=5 miles.
At first we convert 14.5 km to miles. we get,
[tex]\begin{gathered} 14.5\times\frac{5}{8}=\frac{72.5}{8} \\ \text{ =9.0625} \end{gathered}[/tex]So 14.5 km is 9.0625 miles.
Callie's grandmother pledged Rs. 150 for every mile. so for 9.0625 miles it is,
[tex]9.0625\times150=1359.375[/tex]So her grandmother owe Rs. 1359.375