what was the speed during first and also cooldown

Hi Braniac
S = his speed for the 1st 20 mi
(s-2) = His speed for the last 16 mi
We know that :
time= distance/ speed
initial time = cool down time
20/s = 16/(s-2)
Now cross multiply
20(s-2) =16s
20s-40=16s
20s-16s=40
4s = 40
Now we need to divide both sides by 4 so we can find the speed
4s/4 = 40/4
s= 10 mph
His initial speed is 10mph
Now let's find his cool down speed
10-2 = 8mph
His cool down speed is 8mph
I hope that's help :)
If you have any questions please let me know :)