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Weird Questions
Posted:
Thu Apr 04, 2013 7:18 pm
by qwerty123
23. Bea Debest, Ima Slo, and Betsy Luzes run in a 200 meter rce. When Bea crosses the finish line, Ima is 10 m behind Bea. when Ima crosses the finish line, Betsy is 10 m behind Ima. If all 3 runners ran at a constant speed, how far was Betsy from the finish line when Bea won the race?
All are in meters.
A.18
B.19
C.19.5 ANSWER
D.20
E.21.5
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[unparseable or potentially dangerous latex formula] and [unparseable or potentially dangerous latex formula] Find x+y.
Ans 1/2
Thank you
Re: Weird Questions
Posted:
Thu Apr 04, 2013 7:54 pm
by sxk1693
Re: Weird Questions
Posted:
Thu Apr 04, 2013 7:55 pm
by sxk1693
Wait the answer is 3???
I don't get it...My answer is valid...I used my 89 to check.
If you do [1,2;0,.5]^-1 you get [1,4;0,2]
Re: Weird Questions
Posted:
Thu Apr 04, 2013 7:59 pm
by qwerty123
Re: Weird Questions
Posted:
Thu Apr 04, 2013 9:57 pm
by rcoker7
When Bea finishes, she is at 200 meters and Ima is at 190. Their speeds must be in a ratio 20/19. The same is true of Ima compared to Betsy, so Betsy's speed compared to Bea's is 19^2/20^2. When Bea is at 200m, Betsy's position will be this ratio * 200m which gives 361/2=180.5.
Thus C
Re: Weird Questions
Posted:
Thu Apr 04, 2013 9:58 pm
by Fredfredburger
You have two distance equations with runners a, b, and c and 2 different times. First is the first time, [unparseable or potentially dangerous latex formula]
[unparseable or potentially dangerous latex formula] or [unparseable or potentially dangerous latex formula]
[unparseable or potentially dangerous latex formula]
Plugging in the first value into the second equation we get
[unparseable or potentially dangerous latex formula]
Now do the same thing again for the second two runners, you'll get the same thing.
[unparseable or potentially dangerous latex formula]
Substituting in the equation we had for [unparseable or potentially dangerous latex formula] we get
[unparseable or potentially dangerous latex formula]
Now we want to find the distance [unparseable or potentially dangerous latex formula] traveled at [unparseable or potentially dangerous latex formula]. Use the distance formula.
[unparseable or potentially dangerous latex formula]
If you recall from our very first equation we know that [unparseable or potentially dangerous latex formula], so plugging that in we get
[unparseable or potentially dangerous latex formula]
[unparseable or potentially dangerous latex formula]
Uups, look like I got beat to the punch, oh well.