since each hour is 3/8 of a tone then, namely how many times does 3/8 go into 24? well, is just their quotient.
[tex]\bf 24\div\cfrac{3}{8}\implies \cfrac{24}{1}\div\cfrac{3}{8}\implies \cfrac{24}{1}\cdot\cfrac{8}{3}\implies \cfrac{8}{1}\cdot \cfrac{8}{1}\implies 64[/tex]