spped problem

Jan 2010
160
10
Jupimar
A privateer discovers a merchantman 10 miles to leeward at 11:45 a.m. and there being a good breeze bears down upon her at 11mph while the merchantman can only make 8 mph in her attempt to escape.
After a two hour chase, the top sail of the privateer being carried away, she can make only 17 miles while the merchantman makes 15. The privateer will overtake the merchantman at:

My answer was 3:45 pm. I got it wrong.
The wording of this problem is soooooo weird.
 
Jan 2010
160
10
Jupimar
The answer is 5:30 p.m.
How in the world do you get 5:30 P.M.?

this problem is from a 1950s Math Contest and I don't want to skip this one.(unless the problem is missing info) I'm usually very good at speed problems.(Nerd)

Help Please!!!!!!!



 
Apr 2009
121
2
california
Hi Ronsy,

I think 5:30 p.m. is correct.

Try to set up equations for the problem.

At 1:45 they are 4 miles apart.
Then set up t as the time it will take for them to meet.
And the distance each has to cover as D and D+ 4

Then the rate of merchantguy X t = D

rate of privateguy x t = D + 4


Rate of merchantguy is 8mph so 8t =D
Now it is a bit harder to find the rate of the privateguy but as you proudly said that you are good at rates, I believe you will understand the rate that i set up

17 : 15 = X : 8 so X = 8X17/15

Now you have the rates for both guys you can solve for t and D.

Then you will get t=3hours 45min
 
Jan 2010
160
10
Jupimar
Hi Ronsy,

I think 5:30 p.m. is correct.

Try to set up equations for the problem.

At 1:45 they are 4 miles apart.
Then set up t as the time it will take for them to meet.
And the distance each has to cover as D and D+ 4

Then the rate of merchantguy X t = D

rate of privateguy x t = D + 4


Rate of merchantguy is 8mph so 8t =D
Now it is a bit harder to find the rate of the privateguy but as you proudly said that you are good at rates, I believe you will understand the rate that i set up

17 : 15 = X : 8 so X = 8X17/15

Now you have the rates for both guys you can solve for t and D.

Then you will get t=3hours 45min


I don't get it.