Author |
Topic: Help with math problems!!!! (Read 1344 times) |
|
Mugwump101
Junior Member
 
Gender: 
Posts: 61
|
 |
Help with math problems!!!!
« on: Jan 2nd, 2004, 1:01am » |
 Quote  Modify
|
Here they are:
Mr. Adams will be serving 20 people at a barbeque. He plans to make two hamburgers for each person. Mr. Adams spent $27.00 at the store on the meat, which sells for $2.25 per pound. If Mr. Adams wants to make all the hamburgers the saze size, what will be the size, in pounds, of each hamburger?
and
Dave wants to cut a 20-foot-long piece of wood into pieces that are either 5 feet or 2 feet long. He must have at least one of each lengt and have no wood left over. What is the greatest number of pieces he can cut from this piece of wood?
|
|
 IP Logged |
"When I examine myself and my methods of thought, I come to the conclusion that the gift of fantasy has meant more to me than my talent for absorbing positive knowledge. "~ Albert Einstein
|
|
|
ThudnBlunder
wu::riddles Moderator
Uberpuzzler
The dewdrop slides into the shining Sea
Gender: 
Posts: 4489
|
|
Re: Help with math problems!!!!
« Reply #1 on: Jan 2nd, 2004, 4:20am » |
Quote Modify
|
Can't do your homework, huh?
1) Quote:| Mr. Adams will be serving 20 people at a barbeque. He plans to make two hamburgers for each person. |
|
So how many hamburgers will he need?
Quote:| Mr. Adams spent $27.00 at the store on the meat, which sells for $2.25 per pound. |
|
So how many pounds of meat did he buy?
Quote:| If Mr. Adams wants to make all the hamburgers the saze size, what will be the size, in pounds, of each hamburger? |
|
Divide the 2nd answer by the 1st answer and you are done.
2) Quote:| What is the greatest number of pieces he can cut from this piece of wood? |
|
Well, we will need to use as few as possible of the longer (5') pieces.
But we must have at least one of them.
So start with one of them and add 2' pieces until you get to exactly 20'.
If that doesn't work, you will just have to try beginning with two 5' pieces, and add 2' pieces.
|
| « Last Edit: Jan 7th, 2004, 10:23pm by ThudnBlunder » |
IP Logged |
THE MEEK SHALL INHERIT THE EARTH.....................................................................er, if that's all right with the rest of you.
|
|
|
Sir Col
Uberpuzzler
impudens simia et macrologus profundus fabulae
Gender:
Posts: 1825
|
|
Re: Help with math problems!!!!
« Reply #2 on: Jan 2nd, 2004, 11:53am » |
Quote Modify
|
on Jan 2nd, 2004, 1:01am, Mugwump101 wrote:| Dave wants to cut a 20-foot-long piece of wood into pieces that are either 5 feet or 2 feet long. He must have at least one of each lengt and have no wood left over. What is the greatest number of pieces he can cut from this piece of wood? |
|
If he cut 5 feet from one end, why can't he cut the remaining length into lengths of 2 feet?
What if he cut two 5 feet lengths?
What about three 5 feet lengths?
Why can't he cut four 5 feet lengths?
I think you've got enough there to answer your problem. 
|
|
IP Logged |
mathschallenge.net / projecteuler.net
|
|
|
Mugwump101
Junior Member
Gender:
Posts: 61
|
|
Re: Help with math problems!!!!
« Reply #3 on: Jan 2nd, 2004, 8:20pm » |
Quote Modify
|
Thank you so much. But the thing is for the first one it turns out to be a decimal. Would that be allowed?
The second had one mistake I forgot to add the 4 but the concept of it is that, you add the pieces to equal 20? Um, don't I divide it?
|
|
IP Logged |
"When I examine myself and my methods of thought, I come to the conclusion that the gift of fantasy has meant more to me than my talent for absorbing positive knowledge. "~ Albert Einstein
|
|
|
Sir Col
Uberpuzzler
impudens simia et macrologus profundus fabulae
Gender:
Posts: 1825
|
|
Re: Help with math problems!!!!
« Reply #4 on: Jan 3rd, 2004, 2:43am » |
Quote Modify
|
Quote:| But the thing is for the first one it turns out to be a decimal. Would that be allowed? |
|
It would have to be if you wanted the correct answer.
I don't follow your point about a mistake on the 2nd one: "I forgot to add the 4" Where?
Quote:| but the concept of it is that, you add the pieces to equal 20? Um, don't I divide it? |
|
You may never have thought about it like this before, but division is repeated subtraction, just as multiplication is repeated addition.
For example, 4 times 3, means what do we get if we add 4 lots of 3. Answer: 3+3+3+3=12.
Similarly, 12 divided by 3, means how many can 3 be taken from 12? Answer: 12–3=9, 9–3=6, 6–3=3, 3–3=0, so 4 times.
It even works for fractions:
2.5 times 4 = 4 + 4 + 2 (literally two fours and one half of four) = 10
10 divided by 4: 10–4=6, 6–4=2, and 2 is one half of 4; that is, 10/4 = 2.5.
That is why we talk about division and multiplication being inverse operations (one un-does the other). It also explains why your teacher will one day make a point about multiplication being commutative; that is, 4 times 3 = 3 times 4. It may seem obvious when you know off-by-heart that both give an answer of 12, but when we say that 3+3+3+3=4+4+4, it suddenly looks so much more impressive.
|
| « Last Edit: Jan 4th, 2004, 11:19am by Icarus » |
IP Logged |
mathschallenge.net / projecteuler.net
|
|
|
Mugwump101
Junior Member
Gender:
Posts: 61
|
|
Re: Help with math problems!!!!
« Reply #5 on: Jan 4th, 2004, 11:55am » |
Quote Modify
|
THanks a lot the information about the repeated process is very clever, and I really appreaciate your time for the lecture. btw... the 4 is 4 feet.
Dave wants to cut a 20-foot-long piece of wood into pieces that are either 5 feet or 4 feet or 2 feet long. He must have at least one of each lengt and have no wood left over. What is the greatest number of pieces he can cut from this piece of wood?
So basically I subtract 20 by all the measure with each different number. what I mean is:
20-5=15-4=11-2=9-5=4-4=0
And then I count how many pieces I cut it from? I got 5 pieces so far, and continue with:
20-4=16-5=11-2=9-4=5-5=0
And I do a different pattern continueous until I've done all with the numbers, or is it something else I'm not understanding?
Sorry to keep wasting your time on such easy problems! I'm really am sorry, but... I can't take in a lot of math so quickly.
And yet I REALLY REALLY appreaciate ALL your help. Thank you so much!!
|
|
IP Logged |
"When I examine myself and my methods of thought, I come to the conclusion that the gift of fantasy has meant more to me than my talent for absorbing positive knowledge. "~ Albert Einstein
|
|
|
Sir Col
Uberpuzzler
impudens simia et macrologus profundus fabulae
Gender:
Posts: 1825
|
|
Re: Help with math problems!!!!
« Reply #6 on: Jan 4th, 2004, 3:07pm » |
Quote Modify
|
It's a little trickier if you've got three different lengths. As you need one of each length: 2+4+5=11, and 20–11=9. That is, we have no choice over the first three lengths we take.
Now we have 9 feet left over, and we're trying to get as many cuts as possible from this length. As 9 is odd, you must take at least one 5': 9–5=4. Remember we're trying to get as many cuts as possible, so given the choice will you take one 4' or two 2', which will you go for?
|
|
IP Logged |
mathschallenge.net / projecteuler.net
|
|
|
Icarus
wu::riddles Moderator
Uberpuzzler
Boldly going where even angels fear to tread.
Gender:
Posts: 4863
|
|
Re: Help with math problems!!!!
« Reply #7 on: Jan 5th, 2004, 7:21pm » |
Quote Modify
|
on Jan 4th, 2004, 11:55am, Mugwump101 wrote:| Sorry to keep wasting your time on such easy problems! I'm really am sorry, but... I can't take in a lot of math so quickly. |
|
Never apologize for asking about what you do not know. Never apologize for not knowing what you have ernestly attempted to figure out (if your attempt was not ernest, then you would have something to apologize for, but if that were the case, you wouldn't be asking here in the first place).
In neither case do you have anything to regret, and only a fool would berate you for it. Sir Col is a teacher of mathematics, T&B is well-educated in mathematics. I am sure that neither believes you have wasted their time. The only reason some others have not stepped in to answer also is that T&B & Sir Col have already said what we would have.
|
|
IP Logged |
"Pi goes on and on and on ...
And e is just as cursed.
I wonder: Which is larger
When their digits are reversed? " - Anonymous
|
|
|
Mugwump101
Junior Member
Gender:
Posts: 61
|
|
Re: Help with math problems!!!!
« Reply #8 on: Jan 5th, 2004, 10:30pm » |
Quote Modify
|
Thanks alot I understand it better now. I finally get the concept of making many possible ways, and gettting the total pieces Dave needs.
And thanks alot Icarus for those kind words. I never knew Sir Col was a teacher. That's fascinating, no wonder Sir Col's teaching are very clear, and understandable ^_^. T and B was also helpful.
Now that I solved everything, I want to Thank everything that helped me. I really REALLY appreciate it! Thank you so very much!
|
|
IP Logged |
"When I examine myself and my methods of thought, I come to the conclusion that the gift of fantasy has meant more to me than my talent for absorbing positive knowledge. "~ Albert Einstein
|
|
|
|
RIDDLES SITE
WRITE MATH!
Home 
Help 
Search 
Members 
Login 
Register
Reply
Notify of replies
Send Topic
Print