Two planes flying opposite directions (north and south) pass each other 80 miles apart at the same altitude. The northbound plane is flying 200 mph (miles per hour) and the southbound plane is flying 150 mph. When are the planes 200 miles apart? (Round your answer to one decimal place.)
Let after t hours planes will be 500 miles apart.
Then EB = 200t BC = 150t
Therefore, EC = EB + BC = 350t
It's given that DC = 200 miles
By Pythagoras theorem again,
DC² = EC²+ DE²
(200)²= (350t)²+ (80)²
40000 = 122500t² + 6400
400=1225t² + 64
1225t² = 336
t² = 0.27438571 t=0.52 ≈ .52 hours = 31 mins
is the correct or did I do something wrong?
I recall this same post with the same solution posted yesterday, but
with the Search feature of this webpage not working and not working for a couple of years now, ATTN. WEBMASTER, I can't find it.
I agree with the solution, I got the same thing
Your question asks for one decimal place but doesn't say what units
in hours, it would be t = .5 hours
in minutes it would be 31.4 minutes
try that, if not correct they are wrong.