We can calculate the percent of change by means of the following formula:
[tex]change=\frac{x2-x1}{x1}\times100[/tex]Where x2 is the new value and x1 is the original value.
In this case, we go from 60 to 24, then the original value (x1) was 60 and the new value (x2) is 24, by replacing these values into the above equation, we get:
[tex]change=\frac{24-60}{60}\times100=-60[/tex]Then, the percent of change equals -60%