In order to determine the time Josh takes to run, just calculate 3/5 of 4 3/4.
Proceed as follow:
express 4 3/4 as a normal fraction:
4 3/4 = 4/1 + 3/4 = (16 + 3)/4 = 19/4
calculate the pŕoduct between 19/4 and 3/5:
3/5 x 19/4 = 57/20
Hence, Josh takes 57/20 hours running at the gym