David W. answered • 08/18/18

I'll help you understand math!

The end of the problem is missing, but let's say it took 2 hours.

2(j + j/2) = 10.5

3j/2 = 21

3j = 42

j = 14 mph

His jogging speed was 14 mph and his walking speed was 14/2 = 7 mph.