Icompleted 60 jumping jacks in one minute. what is my dependent and independent variable ? ?

J(m)=60m

That is the number of jumping jacks with respect to the number of minutes.

So the number of jumping jacks depends upon the number of minutes.  Meaning that the number of minutes, m, is the independent variable and jumping jacks, j, is the dependent variable.

The year before the 10s so it was like when caveman were alive