Percentage help - Sitcoms Online Message Boards

Kay Scarpetta · 09-21-2003, 11:41 AM

I'm in 9th grade and can do Algebra, Geometry and some basic Trig, meanwhile I sit here for a half hour trying to figure out this problem on your average percentages. Oh yes... I'm brilliant all right. [/sarcasm]

Can anyone help me on this?! It would be forever appreciated... and you'd get a cookie too.

#22. During a special sale, the price of a television is reduced by 10% the first day of the sale and an additional 4% for each successive day of the sale.

a. If the sale price of the TV after 2 days is $80, what was the original price of the TV? Show how you found your answer.

b. After 4 days, the new price of the television will be what percent of the original price of the TV? Round your answer to the nearest percent and show how you found your answer.

c. If the original price of the TV was $180, after how many days will the price of the television be less than $150?

BrandonS · 09-21-2003, 12:12 PM

Quote:

Originally posted by Miss Karly
I'm in 9th grade and can do Algebra, Geometry and some basic Trig, meanwhile I sit here for a half hour trying to figure out this problem on your average percentages. Oh yes... I'm brilliant all right. [/sarcasm]

Can anyone help me on this?! It would be forever appreciated... and you'd get a cookie too.

#22. During a special sale, the price of a television is reduced by 10% the first day of the sale and an additional 4% for each successive day of the sale.

a. If the sale price of the TV after 2 days is $80, what was the original price of the TV? Show how you found your answer.

I'll get you started with part (a). It's kind of hard with only the keyboard symbols, but if unknown original price is X, then:

X (.9)(.96) = 80 (Note: .9 comes from 10% off 1st day and .96 comes from 4% off 2nd day)

Dividing both sides of the equation by (.9)(.96):

X = 80/((.9)(.96)) = 80/.864 = 92.593... or 92.59 to the nearest cent

Also, I'm using the standard algebra notation where putting numbers next to each other implies multiplication even without a "times" symbol.

Kay Scarpetta · 09-21-2003, 12:21 PM

Quote:

Originally posted by BrandonS
I'll get you started with part (a). It's kind of hard with only the keyboard symbols, but if unknown original price is X, then:

X (.9)(.96) = 80 (Note: .9 comes from 10% off 1st day and .96 comes from 4% off 2nd day)

X = 80/((.9)(.96)) = 80/.864 = 92.593... or 92.59 to the nearest cent

Also, I'm using the standard algebra notation where putting numbers next to each other implies multiplication even without a "times" symbol.

Oh goodness... I get it. I actually had 96 for part A but for some reason doubted it. Thank you so very much, Brandon. I appreciate it!!

So how would I write this on my paper? Hmm... *thinks* I'm seriously a failure in math...

BrandonS · 09-21-2003, 12:24 PM

Quote:

Originally posted by Miss Karly
Oh goodness... I get it. I actually had 96 for part A but for some reason doubted it. Thank you so very much, Brandon. I appreciate it!!

Once you get used to setting up these word problems with algebra, it gets a lot easier. Good luck, Karly.

P.S.: You might alternatively multiply the two numbers out before dividing, rather than after like I did.

Then you'd have:

.864X = 80
X = 80/.864 = 92.593..... which is 92.59 to the nearest cent. That's a little clearer.

TJL · 09-21-2003, 12:59 PM

Quote:

Originally posted by Miss Karly
I'm in 9th grade and can do Algebra, Geometry and some basic Trig, meanwhile I sit here for a half hour trying to figure out this problem on your average percentages. Oh yes... I'm brilliant all right. [/sarcasm]

Can anyone help me on this?! It would be forever appreciated... and you'd get a cookie too.

#22. During a special sale, the price of a television is reduced by 10% the first day of the sale and an additional 4% for each successive day of the sale.

a. If the sale price of the TV after 2 days is $80, what was the original price of the TV? Show how you found your answer.

b. After 4 days, the new price of the television will be what percent of the original price of the TV? Round your answer to the nearest percent and show how you found your answer.

c. If the original price of the TV was $180, after how many days will the price of the television be less than $150?

How about buying a stereo instead!

Kay Scarpetta · 09-21-2003, 04:05 PM

I'm pretty sure I figured out B and C

And TJL- I know. Why a TV?

¤I Love Clay Aiken¤ · 09-21-2003, 04:18 PM

Quote:

Originally posted by Miss Karly
I'm in 9th grade and can do Algebra, Geometry and some basic Trig, meanwhile I sit here for a half hour trying to figure out this problem on your average percentages. Oh yes... I'm brilliant all right. [/sarcasm]

Can anyone help me on this?! It would be forever appreciated... and you'd get a cookie too.

#22. During a special sale, the price of a television is reduced by 10% the first day of the sale and an additional 4% for each successive day of the sale.

a. If the sale price of the TV after 2 days is $80, what was the original price of the TV? Show how you found your answer.

b. After 4 days, the new price of the television will be what percent of the original price of the TV? Round your answer to the nearest percent and show how you found your answer.

c. If the original price of the TV was $180, after how many days will the price of the television be less than $150?

Oh I love word problems!! But hate %'s! Blech!! Ok, Im seriously writing on paper with a calculator.. lets see how long it takes me to figure this out.

Ok, I thought I had it, but now Im just confusing myself. I came up with the starting price of $115.50, with a 2nd guess of $90.

The last part I came up with 4 days.

Hollow · 09-21-2003, 05:21 PM

i flunked algebra so these are prolly wrong.

a. i got $91... since its 2 days after the first day of the sale it would be 14% off right? and wouldnt you solve 80 x .14? thats 11.2 and 80 + 11.2 = 91.2 and i rounded it. *shrugs*

b. $68.98. i guess i had to solve 91 x .22 and that came out to be 22.02... then i subtracted 22.02 from 91 and thats 68.98.

c. ok i might have messed up here but i got 3 days. 10% of 180 would be 18 since 180 x .10 = 18 right? so 180 - 18 = 162... 4% of 180 is 7.2 (180 x .04 = 7.2) and 180 - 18 (1st day) - 7.2 (2nd day) - 7.2 = 147.6.

¤I Love Clay Aiken¤ · 09-21-2003, 05:25 PM

Quote:

Originally posted by ~°Sarah°~
i flunked algebra so these are prolly wrong.

a. i got $91... since its 2 days after the first day of the sale it would be 14% off right? and wouldnt you solve 80 x .14? thats 11.2 and 80 + 11.2 = 91.2 and i rounded it. *shrugs*

b. $68.98. i guess i had to solve 91 x .22 and that came out to be 22.02... then i subtracted 22.02 from 91 and thats 68.98.

c. ok i might have messed up here but i got 3 days. 10% of 180 would be 18 since 180 x .10 = 18 right? so 180 - 18 = 162... 4% of 180 is 7.2 (180 x .04 = 7.2) and 180 - 18 (1st day) - 7.2 (2nd day) - 7.2 = 147.6.

14% is different from 10% plus an additional 4%. Say I bought a shirt for $50. If they had a 10% off say it would be $45. If the next day they took off an extra 4%, itd be $43.20. But if it was $50 and were selling it for 14% off, it would be $43.

Hollow · 09-21-2003, 05:35 PM

Quote:

Originally posted by ¤MsConanOBrien¤
14% is different from 10% plus an additional 4%. Say I bought a shirt for $50. If they had a 10% off say it would be $45. If the next day they took off an extra 4%, itd be $43.20. But if it was $50 and were selling it for 14% off, it would be $43.

oic... i'll prolly try it again later.

Kay Scarpetta · 09-21-2003, 07:27 PM

Quote:

Originally posted by ¤MsConanOBrien¤

The last part I came up with 4 days.

I got 4 days too! Yay. I forgot how I did it, but I defintely got 4 days!

BrandonS · 09-21-2003, 08:44 PM

The idea that the percentages are just additive, i.e.: 10% off after 1 day, 14% after 2 days, 18% after 3 days, and 22% after four days might have been a possible interpretation of the question, except for part (b), which asks:

b. After 4 days, the new price of the television will be what percent of the original price of the TV? Round your answer to the nearest percent and show how you found your answer.

Why would you have to round your answer to the nearest percent if the intention had been for the percentages to just add? In this case the answer would have been 100% - 22% or 78%, which would require no rounding. That's why my original interpretation of the instructions still seems right to me.

BrandonS · 09-21-2003, 08:50 PM

If my original interpretation of the setup is correct, then for part (c):

Original price = $180
After 1 day = $180 (.9) = $162
After 2 days = $162 (.96) = $155.52
After 3 days - $155.52 (.96) = $149.2992 or $149.29 to the nearest cent, which is less than $150

09-21-2003, 11:41 AM	#1
Kay Scarpetta Defy Gravity 8.26.05 Forum Superstar Join Date: Jul 04, 2001 Location: La Vie Boheme Posts: 28,013	Percentage help I'm in 9th grade and can do Algebra, Geometry and some basic Trig, meanwhile I sit here for a half hour trying to figure out this problem on your average percentages. Oh yes... I'm brilliant all right. [/sarcasm] Can anyone help me on this?! It would be forever appreciated... and you'd get a cookie too. #22. During a special sale, the price of a television is reduced by 10% the first day of the sale and an additional 4% for each successive day of the sale. a. If the sale price of the TV after 2 days is $80, what was the original price of the TV? Show how you found your answer. b. After 4 days, the new price of the television will be what percent of the original price of the TV? Round your answer to the nearest percent and show how you found your answer. c. If the original price of the TV was $180, after how many days will the price of the television be less than $150?
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09-21-2003, 08:44 PM	#12
BrandonS Member Forum Fanatic Join Date: Aug 18, 2002 Posts: 8,824	The idea that the percentages are just additive, i.e.: 10% off after 1 day, 14% after 2 days, 18% after 3 days, and 22% after four days might have been a possible interpretation of the question, except for part (b), which asks: b. After 4 days, the new price of the television will be what percent of the original price of the TV? Round your answer to the nearest percent and show how you found your answer. Why would you have to round your answer to the nearest percent if the intention had been for the percentages to just add? In this case the answer would have been 100% - 22% or 78%, which would require no rounding. That's why my original interpretation of the instructions still seems right to me.
	Last edited by BrandonS; 09-21-2003 at 08:56 PM.

09-21-2003, 04:05 PM	#6
Kay Scarpetta Defy Gravity 8.26.05 Forum Superstar Join Date: Jul 04, 2001 Location: La Vie Boheme Posts: 28,013	I'm pretty sure I figured out B and C And TJL- I know. Why a TV?

09-21-2003, 05:21 PM	#8
Hollow Member Forum Superstar Join Date: Dec 16, 2001 Posts: 30,406	i flunked algebra so these are prolly wrong. a. i got $91... since its 2 days after the first day of the sale it would be 14% off right? and wouldnt you solve 80 x .14? thats 11.2 and 80 + 11.2 = 91.2 and i rounded it. shrugs b. $68.98. i guess i had to solve 91 x .22 and that came out to be 22.02... then i subtracted 22.02 from 91 and thats 68.98. c. ok i might have messed up here but i got 3 days. 10% of 180 would be 18 since 180 x .10 = 18 right? so 180 - 18 = 162... 4% of 180 is 7.2 (180 x .04 = 7.2) and 180 - 18 (1st day) - 7.2 (2nd day) - 7.2 = 147.6.

09-21-2003, 08:50 PM	#13
BrandonS Member Forum Fanatic Join Date: Aug 18, 2002 Posts: 8,824	If my original interpretation of the setup is correct, then for part (c): Original price = $180 After 1 day = $180 (.9) = $162 After 2 days = $162 (.96) = $155.52 After 3 days - $155.52 (.96) = $149.2992 or $149.29 to the nearest cent, which is less than $150