Question 183266
Distance(d) equals Rate(r) times Time(t) or d=rt;  r=d/t and t=d/r
Let r=rate of the current
And let s=speed of boat in still water

Upstream:
s-r=222/6=37-----------------eq1
Downstream:
s+r=222/4=55.5------------------eq2

add eq1 and eq2
2s=92.5
s=46.25 mph-------------speed of boat in still water
from eq1
46.25-r=37
r=9.25 mph------------------------speed of the current

Hope this helps---ptaylor