Total Posts:11|Showing Posts:1-11

# Help with algebra problem

 Posts: 3 Add as FriendChallenge to a DebateSend a Message 9/19/2012 2:37:04 PMPosted: 5 years agoThere is a boat going from point A to B. It is 180 km from A to B. From point A to B is going downstream, so it only takes 10 hours. To get from point B to A, is upstream so it takes 15 hours. It rains so the river moves faster, and point A to B only takes 9 hours now. Now, how long will it take to get from point B to point A? Can you please help me with this? Explain how to do this problem.
 Posts: 14,501 Add as FriendChallenge to a DebateSend a Message 9/19/2012 3:04:39 PMPosted: 5 years ago16 hours I guess. The rain makes downstream stronger, so upstream would take longer.#StandWithBossy
 Posts: 14,501 Add as FriendChallenge to a DebateSend a Message 9/19/2012 3:15:54 PMPosted: 5 years agoAt 9/19/2012 3:04:39 PM, bossyburrito wrote:16 hours I guess. The rain makes downstream stronger, so upstream would take longer.I just realised how stupid my answer was...#StandWithBossy
 Posts: 14,501 Add as FriendChallenge to a DebateSend a Message 9/19/2012 3:19:03 PMPosted: 5 years agoA to b = 18 kphB to a = 12 kphA to b with rain = 20 kphB to a with rain = 10 kph180/10 = 18 hours#StandWithBossy
 Posts: 2,900 Add as FriendChallenge to a DebateSend a Message 9/19/2012 3:23:45 PMPosted: 5 years agoAt 9/19/2012 2:37:04 PM, hellomynameisbob wrote:There is a boat going from point A to B. It is 180 km from A to B. From point A to B is going downstream, so it only takes 10 hours. To get from point B to A, is upstream so it takes 15 hours. It rains so the river moves faster, and point A to B only takes 9 hours now. Now, how long will it take to get from point B to point A? Can you please help me with this? Explain how to do this problem.By the time I'm done, someone else will probably have done it too, and much better.The boat moves at rate x, and the river moves at rate y. When going downstream, the boat moves at rate x + y for 10 hours. The equation is:10(x + y) = 180x = 18 - yGoing upstream, the rate is x - y, and it takes 15 hours. The equation is:15(x - y) = 180x - y = 12x = y + 12Substitute:18 - y = 12 + y18 - 12 = 2y6 = 2y3 = yx = 3 + 12x = 15In the next part, the current of the river (y) increases. To travel the same 180km, it now takes only 9 hours (downstream). We can preserve the x value, because the boat's speed does not change.9(x + y) = 180x + y = 2015 + y = 20y = 5Now that we know the new rate of the current, we can solve for the time it takes to travel upstream against the current. The time it takes is a new variable, z.z(15 - 5) = 18010z = 180z = 18Therefore, it takes 18 hours to travel upstream against the new current.'When the Spirit of truth comes, he will guide you into all the truth; for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come.' - John 16:13
 Posts: 2,900 Add as FriendChallenge to a DebateSend a Message 9/19/2012 3:24:08 PMPosted: 5 years agoAnd I was right. Bossy beat me.'When the Spirit of truth comes, he will guide you into all the truth; for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come.' - John 16:13
 Posts: 1,058 Add as FriendChallenge to a DebateSend a Message 9/19/2012 5:13:55 PMPosted: 5 years agoWho's the Fvcking douche who invented algebra?http://www.terriblefate.com...
 Posts: 13,062 Add as FriendChallenge to a DebateSend a Message 9/19/2012 5:15:29 PMPosted: 5 years agoAt 9/19/2012 5:13:55 PM, MilitaryAtheist wrote:Who's the Fvcking douche who invented algebra?http://en.wikipedia.org...-~-~-~-~-~-~-~-OBERHERR'S SIGNATURE-~-~-~-~-~-~-~- Official Enforcer for the DDO Elite(if they existed). "Cases are anti-town." - FourTrouble -~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
 Posts: 1,058 Add as FriendChallenge to a DebateSend a Message 9/19/2012 5:16:47 PMPosted: 5 years agoAt 9/19/2012 5:15:29 PM, OberHerr wrote:At 9/19/2012 5:13:55 PM, MilitaryAtheist wrote:Who's the Fvcking douche who invented algebra?http://en.wikipedia.org...Had to be Arabic.http://www.terriblefate.com...
 Posts: 14,501 Add as FriendChallenge to a DebateSend a Message 9/19/2012 6:10:40 PMPosted: 5 years agoAt 9/19/2012 3:24:08 PM, AlwaysMoreThanYou wrote:And I was right. Bossy beat me.I couldn't understand a thing you said.#StandWithBossy
 Posts: 5,093 Add as FriendChallenge to a DebateSend a Message 9/19/2012 6:19:14 PMPosted: 5 years agoAt 9/19/2012 5:16:47 PM, MilitaryAtheist wrote:At 9/19/2012 5:15:29 PM, OberHerr wrote:At 9/19/2012 5:13:55 PM, MilitaryAtheist wrote:Who's the Fvcking douche who invented algebra?http://en.wikipedia.org...Had to be Arabic.Aren't numbers? hah"If you are a racist I will attack you with the north"- Abraham Lincoln "Do not wear clothing woven of two kinds of material" - Leviticus 19 19 "War is a racket" - Smedley Butler