Question 867155
If just this much is shown to you, can you finish solving?


r = speed without wind
t = time to go 3600 km against the wind
{{{2/3}}} hour = 40 minutes
Key Idea: RT=D using R rate, T time, D distance



________________speed_________time__________distance
WITH WIND_______r+30__________{{{t-2/3}}}_________3600
AGAINST WIND____r-30___________t____________3600