MATH: word problems?

👨🏻‍🏫 學術台數學

[匿名]

2007-12-13 1:34 pm

For an aution item, the bid starts at $100 and increases every minute. In how many minutes will the bid go over $2,500?

Sharon uses her initials, SLF, for her password. How many different three-letter passwords can she make with these letters?

In how many ways can you make 45 cents in change using only nickels, dimes, and quarters?

更新1:

#1. Sorry..it increases by 50%

回答 (9)

[匿名]

2007-12-13 2:38 pm

✔ 最佳答案

1)8 minutes...you'll be making around $2562

2) SLF
SFL
FSL
FLS
LSF
Lfs

3) q + 2d
q + d + 2n
q + 4n
4d + n
3d + 3n
2d + 5n
d + 7n
9n

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[匿名]

2007-12-13 1:46 pm

1. What is the amount of increase each minute? The bid starts at $100 but does the bid increase $100 each minute also? Need that information to solve the problem.

2. You have: SLF, SFL, FSL, FLS, LFS, and LSF

3. The least number of coins would be 1 quarter and 2 dimes.
Your problem did not say if you had to use at least one of each or if you could have, for example, 9 nickels, or 7 nickels and 1 dime, etc.

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[匿名]

2007-12-13 1:46 pm

1) Increases by how much each minute? If by another $100, then the problem boils down to:
100 + 100x > 2500
1 + x > 25
x > 24
Where 'x' is the number of minutes.

2) Write them down, there aren't that many ;)
FLS
FSL
LFS
LSF
SFL
SLF
The number of different arrangements of different characters or numbers is equal to n! (1*2*3*4*...*[n-1]*n), where 'n' is the number of characters or numbers. So in this case, 'n' is 3, so 3! is 1*2*3 which is 6.

3) I'll list the combinations here, where d = dimes, n = nickels, and q = quarters:

q + 2d
q + d + 2n
q + 4n
4d + n
3d + 3n
2d + 5n
d + 7n
9n

I don't think I've missed any combinations out, but I make it 8 ways.

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[匿名]

2007-12-13 1:43 pm

first problem:
let m = number of minutes
We want 100m + 100 = 2500
100m = 2400
m = 24 minutes

second: work it out - make a list:
SLF, SFL, FLS, FSL, LFS, LSF
that's it -- can you come up with any others??

third: play with this one.
9 x5 (that's just nickels)
4x10 + 5 (that's 4 dimes and one nickel)
3x10 + 3x5(3dimes, 3 nickels)
2x10 + 5x5(2 dimes, 5 nickels)
1x10 + 7x5(1 dime, 7 nickels)
1x25 +4x5(1 quarter, 4 nickels)
1x25 + 2x10(1 quarter, 2 dimes)
1x25 + 1x10 + 2x5(1 quarter, 1 dime, 2 nickels)
I think that's it. Can you come up with any more?

:)

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pyrodude1031

2007-12-13 1:42 pm

for Q1, how does the item increase? exponentially? different amounts each minute? constant difference?

for Q2, 6, becasue the first letter could have SLF inside, the next letter could only be one of the "2" left-over letters, and lastly one letter is left, hence 3x2x1 = 6

Q3. sorry, no idea what nickels, dimes and quarters are.

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[匿名]

2007-12-13 1:42 pm

Not enough information. How much does the bid increase every minute?

6
SLF
SFL
LFS
LSF
FSL
FLS

I believe 8
QDD
QDNN
QNNNN
DDDDN
DDDNNN
DDNNNNN
DNNNNNNN
NNNNNNNNN

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[匿名]

2007-12-13 1:36 pm

Use algebra to solve ;D

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[匿名]

2007-12-13 1:42 pm

1)_If the bid increses by $1 per minute it will take 80 minutes ( I think) because $2500-$100= $2400/60=80 but I've got a feeling I've done something wrong. Double check it!!
2) Well you can have 6 different ways using theses three letters_You can put S- slf sfl
L- lsf lfs
F- fsl fls so that makes 6 I'm afraid I'm not sure about the last one. I'm not american I'm english. Hope that helped

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[匿名]

2016-12-18 5:49 am

If some thing is 40% smaller, you in basic terms subtract 40%. So 40% of 40 energy is sixteen: you do this by way of multiplying 40 by way of 0.4. the respond could be 40 - sixteen = 24 A shorter way might in basic terms be to multiply by way of 40 by way of 0.6, considering the fact that that could be a million-0.4.

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