Hi I need help in a math problem plz plz plz i need it today?

Question

OK here is the problem:
"Andy baught a file,a packet of crayons and a calculator
The price of the file is 2 times the price of the crayons
The price of the calculator is 3 times the price of the file
He payed 100$ and they returned to him 0.8$
What is the price of each thing?"

Please I need equations and explanations
Thanks:)

Answer 1

let crayons = x
file = 2x
calculator = 3(2x) = 6x
total = x + 2x + 6x = 9x
amount paid = 100.00 - 0.80 = 99.20

x = 99.20/9 = $11.02

crayons: $11.02
file: $22.04
calculator: $61.33

Answer 2

OK. Call the price of the least expensive thing (the crayons) x.

x = cost of crayons

then (from the problem)

2x = cost of the file
3*(2x) = 6x = cost of calculator

We know that

x+2x + 6x = 100 - .8 = 99.2

so

9x = 99.2 => x = 99.2/9 = 11.02 (rounded to the nearest penny)

so the crayons cost $11.02
the file cost 2*11.02 = $22.04
and the calculator cost 3*22.04 = $66.12

Total cost is 11.02 = 22.04 + 66.12 = 99.18

There is a 2 cent difference because of the round-off error.

And, BTW, this is an example of a *terrible* problem to give a new math student because some numbnuts was too lazy to actually *do* the arithmetic and give the change returned as $.82 in stead of $.8 which leaves the student hopelessly lost and wondering "where did the other 2 cents go to?"


Doug

Answer 3

let x = price of crayons; 2x = price of file; 6x = price of calculator

The way I read the question, all of these goods together cost $99.20 (since Andy got 80 cents change from a $100 bill)

x + 2x + 6x = 99.20
9x = 99.20
x = 11.02222...

The crayons cost $11.02, the file cost $22.04, and the calculator cost $66.13. Because of rounding, those three numbers add up only to $99.19, but the math is correct.

Answer 4

F- File
C- Crayons
R- Calculator

F= 2c
R=3f

r=3 (2c)

To find the price of the crayons

F+R+C=100-change (it's unclear wheither it's 8 cents or 80 cents, I'll call this Q)

2c+C+6C= Q

9C=Q

Divide Q by 9 and that is the price of the crayons.

Then just plug that number to the other equations. Email me if you have any questions

Answer 5

Trying to get someone to do your homework for you? Well, I am feeling generous.. Hehehe.. only once. :P

File = a
Crayons = b
Calculators = c

a = 2b;
c = 3a;
100 - (a + b + c) = 0.80

If a = 2b therefore c = 3(2b)

100 - (2b + b + 6b) = 0.80
9b = 99 1/5
b = (99 1/5)/9 = 11 1/45

In a = 2b therefore a = 22 2/45

and in c= 3a therefore c = 3(22 2/45) = 66 2/15

Answer 6

6x+2x+x=99.2
x=99.2/9 price of crayons
198.4/9 price of file
198.4/3 price of calci
you can check the calculations

Answer 7

x = crayons

2x = file

3(2x) = caculator

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

x + 2x + 3(2x) =100 - 0.8

9x = 99.20

9x/9 = 99.20/9

Dividing both sides by 9

x = 11.02222222

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

11.02222222 + 2(11.02222222) +6(11.02222222 = 99.20

1102222222+ 22.044444444 + 66.13333332 = 99.20

99.19999998 = 99.20

99.19999998 rounded up to 99.20

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

File = 11.02222222 rounded to two decimal places equals $ 11.02

Crayons = 22.044444444 rounded to two decimal places equals $ 22.04

Caculator = 66.13333333 rounded to two decimal places equals $ 66.13

Answer 8

File =X
crayons = 2X
Calclulator = 3 (2x) = 6X

X+ 2X+6X = 100 - 0.8

9x= 99.20

x= 99.20/9 = 11.02

crayons = 11.02
file = 22.04
calculator = 66.12

Answer 9

Let's start with the representations:

Let the

price of the file in $ = f
price of the packet of crayons in $= p
price of the calculator in $ = c

"The price of the file is 2 times the price of the crayons"
would be translated as
(equation 1)f = 2p

"The price of the calculator is 3 times the price of the file"
would be translated as
(equation 2)c=3f

"He payed 100$ and they returned to him 0.8$"
would mean that

you paid ($100 minus $0.8) $99.2. This means that the total price of the things you bought is $99.2.

Thus...

(equation 3)f+c+p = 99.2

now, substitute f in eq. 1 to f in eq. 2

thus
(eq1) f=2p
(eq2) c=3f becomes

f = 2p
c=3f
c=3 (2p) since f=2p. Thus, (equation 4) c=6p

now, substitute f in eq. 1 to f in eq. 3

thus
(eq1) f=2p
(eq3) f+c+p=99.2 becomes

f = 2p
f+c+p=99.2
(2p)+c+p=99.2 since f=2p. Thus,

2p+c+p=99.2
(equation 5) 3p+c=99.2

Now , we have two new equations,

(eq4) c=6p
(eq5) 3p+c=99.2

Now, substitute c in equation 4 to c in equation 5

(eq4) c=6p
(eq5) 3p+c=99.2

becomes

c=6p
3p+c=99.2

3p+(6p)=99.2 since c=6p
9p=99.2

9p/9=99.2/9
----p=$11.02-----

Now that we have found p, we may substitute it to either
equation 4 or equation 5, thus, (I'll use eq 4)

c=6p
c=6(11.02)
----c=$66.13----

Now that we have found p and c, we may substitute it to either
equation 1 or equation 2 or equation 3, thus, (I'll use eq 1)

f=2p
f=2(11.02)
----f=$22.04----

Now we get

----f=$22.04---- price of file
----c=$66.13---- price of the calcuator
----p=$11.02----- price of the packet of crayons


=) Please for this as the best answer. Thank you! ;-)

Answer 10

The equation is a parabola. Graph the parabola first. Then, if it says >, coloration above parabola If it says <, coloration under parabola. If the equation says greater advantageous than or equivalent to OR under or equivalent to, then coloration the parabola itself. if it somewhat is in hassle-free terms greater advantageous than or basically lesser than, use a dashed line to coach the parabola.