Time Relation Problem

[WAN]

Dear folks,
Please review my way of thinking to solve the following question.

Selma and Miriam are racing their sailboats from Miami, Florida to Georgetown, Grand Cayman. The loser must buy the
first round of drinks at their favorite beach bar. At 1 P.M., Selma passes a cruise ship that is anchored 160 miles
away from Georgetown. Selma is traveling at 20 miles per hour. At 2 P.M., Miriam passes the anchored cruise ship.
Miriam is traveling at 24 miles per hour. If they continue traveling at the same rates, when will Miriam overtake
Selma?

A. 7 P.M.
B. 6 P.M.
C. 5:45 P.M.
D. 8 P.M.
E. 6:30 P.M.

Answ.
20(t+1)=24t
t=5
the question ask when Mariam overtake Selma, since Mariam start at 2 P.M, thus
2+7=7 P.M

Kindly correct my answer if there is a mistake.
Thx.

[WAN]

Answ.
20(t+1)=24t
t=5
the question ask when Mariam overtake Selma, since Mariam start at 2 P.M, thus
2+7=7 P.M

small typo
should be 2+5= 7 P.M

Thx again.

[RonPurewal]

please post a source for this problem; we can't answer the problem unless it's sourced, and we'll have to delete the thread fairly soon if no source is provided.

also, grand cayman time is one hour behind miami time, at least while miami is on daylight savings time. since we don't know what time of year it is, or in which time zone the action is happening, we can't answer the question. heh heh.

[WAN]

please post a source for this problem; we can't answer the problem unless it's sourced, and we'll have to delete the thread fairly soon if no source is provided.

also, grand cayman time is one hour behind miami time, at least while miami is on daylight savings time. since we don't know what time of year it is, or in which time zone the action is happening, we can't answer the question. heh heh.

Upz, sorry to not attach the source of question as the following below:
The Delta Course
Daily GMAT Practice Question
April 26, 2008
answer is provided but my approachment is different and i stick to what is Manhattan GMAT Prep (Word Translation) explained:
http://www.deltacourse.com/questions/352312CQ.asp

presumably, time difference is omitted....OR just answer question regardless time difference.

Thx

[StaceyKoprince]

Okay, I'll assume that they are using their own watches to see what time it is - and they don't adjust their watches once they switch time zones. :)

Yes, your solution works!

At the point Selma and Miriam cross paths, they will have gone the same distance from the ship but for different times and at different rates:
.....r......t........d
S..20....t+1....x
M..24...t.........x

20(t+1) = 24t
solve for t, which is the time M spent sailing, and then add to 2p!

Now - something else. Be very careful about the sources from which you study. You'd never see a real GMAT question worded this way - the time zone thing does actually make the problem completely invalid. If you've used all of your OG questions but don't feel ready for the test yet... then you haven't actually learned everything you should've learned from your OG questions. You don't learn much in the first two minutes that you try a problem for the first time. You learn from your extensive analysis of that problem after you've done it for the first time. I spend a minimum of 5 minutes reviewing ANY problem - even easy ones, even ones I get right - and I can easily spend 10, 15, even 20 minutes on more intricate ones! Make sure that you aren't substituting quantity of study for quality.