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Sorry, I seemed to have forgotten how to solve this problem:

465/(x+17) = 363/(x-17)

Solve for x.


Also, here is another math question that I'm not sure how to solve:

A broken clock is set correctly at 12:00 noon. However, it registers only 20 minutes for each hour. In how many hours will it again register the correct time?

a) 0.5
b) 18
c) 24
d) 30
c) 36

By Zerg_Vvins (Zerg_Vvins) on Tuesday, August 12, 2003 - 06:43 pm: Edit

465/(x+17) = 363/(x-17)

465(x-17)=363(x+17)


36 hours? 36/3=12

By Nutmag345 (Nutmag345) on Tuesday, August 12, 2003 - 06:44 pm: Edit

For the second problem the answer is 18.
The logic behind the question is, how many hours will it take for the clock to fall 12 hours (720 min) behind the actual time. Falling 12 hrs behind means the clock is back to showing the actual time. Since the clock falls 40 min behind every hour, 720 min / 40 gives you 18 hours as the answer.

By Zerg_Vvins (Zerg_Vvins) on Tuesday, August 12, 2003 - 06:49 pm: Edit

is the clock a 24 hour clock or a 12 hour clock?

By Avalon87 (Avalon87) on Tuesday, August 12, 2003 - 06:49 pm: Edit

Um, zerg, that's not the answer to the first problem...Someone, please solve for x?! I can't get a type of rate problem if I don't!!!

By Avalon87 (Avalon87) on Tuesday, August 12, 2003 - 06:50 pm: Edit

12

By Aoe2guy (Aoe2guy) on Tuesday, August 12, 2003 - 08:08 pm: Edit

Avalon Zerg's response was not the real answer but the means to get to the answer. Your question was a proportion, and he cross multiplied. All that remains is to distribute and solve for x as a simple algebraic problem.

By Nutmag345 (Nutmag345) on Tuesday, August 12, 2003 - 08:20 pm: Edit

Avalon, is the answer to the second question 18 or 36? I guess if it's a 24 hour clock the answer is 36. I hate it when things like this can get you a wrong answer, even though you actually understand the question.

By Serene (Serene) on Tuesday, August 12, 2003 - 08:32 pm: Edit

Either way go w/ nutmaq's solution. It's good. =)

By Bountyhuntersax (Bountyhuntersax) on Wednesday, August 13, 2003 - 12:23 pm: Edit

456(x-17) = 363(x+17)

456x - (17)(456) = 363x + (17)(363)
456x - 363x = (17)(363)/(456)(17)
93x = 363/456
x = .79605/93

x = .0085597 or x = 121/14136

By Xiggi (Xiggi) on Wednesday, August 13, 2003 - 12:36 pm: Edit

Strange answer

By Zerg_Vvins (Zerg_Vvins) on Wednesday, August 13, 2003 - 12:42 pm: Edit

456(x-17) = 363(x+17)

456x - (17)(456) = 363x + (17)(363)
456x - 363x = (17)(363)/(456)(17) <---- (17)(363)+(456)(17)
93x = 363/456
x = .79605/93

By Tootall (Tootall) on Wednesday, August 13, 2003 - 12:46 pm: Edit

Where did you get this problem from? Nice job Nutmeg.

By Avalon87 (Avalon87) on Wednesday, August 13, 2003 - 02:53 pm: Edit

Sorry about the first question, I blanked out!!! (hitting myself on the head) TOO MUCH STUDYING!!! :o

By Nutmag345 (Nutmag345) on Wednesday, August 13, 2003 - 03:01 pm: Edit

Avalon, what is the answer to the second one? 18 or 36? Just want to know if you can assume that the clock doesn't show AM and PM.

By Zerg_Vvins (Zerg_Vvins) on Wednesday, August 13, 2003 - 03:09 pm: Edit

it's 18, since avalon told us that it's a 12 hour clock

By Funkirabbi (Funkirabbi) on Wednesday, August 13, 2003 - 03:24 pm: Edit

wtf, on the first problem the answer is 138. If you put in 138 for x on each, you get:

465/(138+17) = 3
363/(138-17) = 3

By Zerg_Vvins (Zerg_Vvins) on Wednesday, August 13, 2003 - 03:41 pm: Edit

er.. yes we know that..

By Xiggi (Xiggi) on Wednesday, August 13, 2003 - 03:54 pm: Edit

That's why I wrote "strange answer".

456 is not 465
and / does not mean +

Oh well

By Serene (Serene) on Wednesday, August 13, 2003 - 06:11 pm: Edit

Zerg: Somehow I strongly suspect that you didn't do the clock problem the right way first time. =)

By Zerg_Vvins (Zerg_Vvins) on Wednesday, August 13, 2003 - 06:18 pm: Edit

now now, that's just pure speculation


look at it this way, my answer can be used for both the 12 and 24 hour clock. hehe

By Avalon87 (Avalon87) on Wednesday, August 13, 2003 - 07:10 pm: Edit

the answer to the second one is 18!

By Zerg_Vvins (Zerg_Vvins) on Wednesday, August 13, 2003 - 07:23 pm: Edit

er.. avalon87 you seem obliviou to our previous posts... we sorta figured that the answer is 18 since you told us it's a 12 hour clock

By Serene (Serene) on Wednesday, August 13, 2003 - 07:40 pm: Edit

how could you use 36 for the 12 hour clock? =)

By Student9 (Student9) on Wednesday, August 13, 2003 - 07:57 pm: Edit

wait a minute

465/(x+17) = 363/(x-17)

so

465(x-17)=363(x+17)
465x-7905=363x+6171
102x=14076
x=138

And it does not matter whether it is a 12 or 24 hour clock.

an hour is an hour is an hour.

It asks how many hours not what time it is. 18

By Serene (Serene) on Wednesday, August 13, 2003 - 07:59 pm: Edit

Student9: yes it depends. after 18 hours let's say the correct time is 3 AM, on the 12 clock i'd also show 3 o'clock, on 24 hour clock it'd show 15 o'clock.

By Student9 (Student9) on Wednesday, August 13, 2003 - 09:44 pm: Edit

Just look at the numbers:

3hrs (real) = 1 hour (broken)
6hrs (real) = 2 hours (broken)
9hrs (real) = 3 hour (broken)
12hrs (real) = 4 hours (broken)
15hrs (real) = 5 hour (broken)
18hrs (real) = 6 hours (broken)

18 hours after 12:00 corresponds with 6:00

a) 0.5
b) 18 <=well either way 18 hrs is the first time
it happens
c) 24
d) 30
c) 36

Here's a simple strategy I use in everday life:

It's called "KISS"
"Keep it simple stupid" just assume that it is a standard nondigital 12 hour clock. 18 hrs being the least number of hours, forget about the 24 hour possibility.

anyways, the answer is 18.

ALL YOUR BASE ARE BELONG TO US
SOMEBODY SET UP US THE BOMB
YOU KNOW WHAT YOU DOING?
YOU HAVE NO CHANCE TO SURVIVE MAKE YOUR TIME
HA HA HA HA
TAKE OFF EVERY ZIG
MOVE ZIG
FOR GREAT JUSTICE

By Serene (Serene) on Wednesday, August 13, 2003 - 10:05 pm: Edit

and for the rest of us...
keep it simple smart.
on a test you may not always have the time to plug and check...

By Student9 (Student9) on Wednesday, August 13, 2003 - 10:10 pm: Edit

Serene, relax, I didn't call you or anyone else stupid.

And my method was not exactly "plug and check" It is rather quick actually, you don't have to write EVERYTHING I did.

just chill

P.S> finally got my pic scanned and uploaded.

By Serene (Serene) on Wednesday, August 13, 2003 - 10:14 pm: Edit

well.... what if 18 was choice E? w/o plug and check how could you know to try 18 first? =)

By Student9 (Student9) on Wednesday, August 13, 2003 - 10:17 pm: Edit

U DON'T backsolve with this problem.

I just wrote what goes on in my mind.

U start with 3 hrs real = 1 hour on broken

By Xiggi (Xiggi) on Wednesday, August 13, 2003 - 11:52 pm: Edit

Boy, there is has been much written about this question.

Serene, I answered the question in the same way that Student9 did and it took about 20-30 secs. I guess the only difference is that I put mine horizontally in that quick 3 to 1 pattern.

3-6-9-12-15-18
1-2-3-04-05-06

By the way, I KNEW that the answer would be either 18 or 36 before starting writing. The reason is that ETS, in their infinite wisdom, loves to provide an answer that is exactly double or one-half of the correct answer. It is pattern that shows up 3 or 4 times in every test. I would not say that is 100% reliable but it seems to work very often.