Ratio and Proportion Maths Problem Solving
$begingroup$
A jar contains some cookies. The weight of the jar and cookies is 700g. Meghan eats $frac{4}{5}$ of the cookies.
The weight of the jar and cookies is now 400g.
How much does the jar weigh?
How many cookies were there from the start?
What I did:
$frac{700}{5}$ = 140
700 - 140 = 560
560 - 400 = 160
But I don't know what to do next.
Thank You and Help is appreciated
algebra-precalculus problem-solving word-problem ratio
$endgroup$
|
show 9 more comments
$begingroup$
A jar contains some cookies. The weight of the jar and cookies is 700g. Meghan eats $frac{4}{5}$ of the cookies.
The weight of the jar and cookies is now 400g.
How much does the jar weigh?
How many cookies were there from the start?
What I did:
$frac{700}{5}$ = 140
700 - 140 = 560
560 - 400 = 160
But I don't know what to do next.
Thank You and Help is appreciated
algebra-precalculus problem-solving word-problem ratio
$endgroup$
1
$begingroup$
Looks a bit random and you have poor Meghan eating some of the jar. If X is the weight of the jar and Y the weight of the cookies can you write down two equations relating X and Y?
$endgroup$
– Paul
Sep 29 '18 at 7:48
1
$begingroup$
$x$ + $y$ = 700
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 7:52
1
$begingroup$
Ohh wait is it 1/5
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 7:58
2
$begingroup$
Using simultaneous equations I found out that x = 325 so the jar weighs 325g
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 8:27
1
$begingroup$
Just a poorly worded question. There are 375g of cookies.
$endgroup$
– Paul
Sep 29 '18 at 12:08
|
show 9 more comments
$begingroup$
A jar contains some cookies. The weight of the jar and cookies is 700g. Meghan eats $frac{4}{5}$ of the cookies.
The weight of the jar and cookies is now 400g.
How much does the jar weigh?
How many cookies were there from the start?
What I did:
$frac{700}{5}$ = 140
700 - 140 = 560
560 - 400 = 160
But I don't know what to do next.
Thank You and Help is appreciated
algebra-precalculus problem-solving word-problem ratio
$endgroup$
A jar contains some cookies. The weight of the jar and cookies is 700g. Meghan eats $frac{4}{5}$ of the cookies.
The weight of the jar and cookies is now 400g.
How much does the jar weigh?
How many cookies were there from the start?
What I did:
$frac{700}{5}$ = 140
700 - 140 = 560
560 - 400 = 160
But I don't know what to do next.
Thank You and Help is appreciated
algebra-precalculus problem-solving word-problem ratio
algebra-precalculus problem-solving word-problem ratio
edited Sep 29 '18 at 7:46
N. F. Taussig
45.1k103358
45.1k103358
asked Sep 29 '18 at 7:43
xx_Gcsemathstudent_xxxx_Gcsemathstudent_xx
406
406
1
$begingroup$
Looks a bit random and you have poor Meghan eating some of the jar. If X is the weight of the jar and Y the weight of the cookies can you write down two equations relating X and Y?
$endgroup$
– Paul
Sep 29 '18 at 7:48
1
$begingroup$
$x$ + $y$ = 700
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 7:52
1
$begingroup$
Ohh wait is it 1/5
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 7:58
2
$begingroup$
Using simultaneous equations I found out that x = 325 so the jar weighs 325g
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 8:27
1
$begingroup$
Just a poorly worded question. There are 375g of cookies.
$endgroup$
– Paul
Sep 29 '18 at 12:08
|
show 9 more comments
1
$begingroup$
Looks a bit random and you have poor Meghan eating some of the jar. If X is the weight of the jar and Y the weight of the cookies can you write down two equations relating X and Y?
$endgroup$
– Paul
Sep 29 '18 at 7:48
1
$begingroup$
$x$ + $y$ = 700
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 7:52
1
$begingroup$
Ohh wait is it 1/5
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 7:58
2
$begingroup$
Using simultaneous equations I found out that x = 325 so the jar weighs 325g
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 8:27
1
$begingroup$
Just a poorly worded question. There are 375g of cookies.
$endgroup$
– Paul
Sep 29 '18 at 12:08
1
1
$begingroup$
Looks a bit random and you have poor Meghan eating some of the jar. If X is the weight of the jar and Y the weight of the cookies can you write down two equations relating X and Y?
$endgroup$
– Paul
Sep 29 '18 at 7:48
$begingroup$
Looks a bit random and you have poor Meghan eating some of the jar. If X is the weight of the jar and Y the weight of the cookies can you write down two equations relating X and Y?
$endgroup$
– Paul
Sep 29 '18 at 7:48
1
1
$begingroup$
$x$ + $y$ = 700
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 7:52
$begingroup$
$x$ + $y$ = 700
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 7:52
1
1
$begingroup$
Ohh wait is it 1/5
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 7:58
$begingroup$
Ohh wait is it 1/5
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 7:58
2
2
$begingroup$
Using simultaneous equations I found out that x = 325 so the jar weighs 325g
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 8:27
$begingroup$
Using simultaneous equations I found out that x = 325 so the jar weighs 325g
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 8:27
1
1
$begingroup$
Just a poorly worded question. There are 375g of cookies.
$endgroup$
– Paul
Sep 29 '18 at 12:08
$begingroup$
Just a poorly worded question. There are 375g of cookies.
$endgroup$
– Paul
Sep 29 '18 at 12:08
|
show 9 more comments
2 Answers
2
active
oldest
votes
$begingroup$
You should assign letters to the unknown quantities and form simultaneous equations from them.
I would let the jar's weight be $J$ and the total weight of the cookies be $C$.
The first statement tells you:
$$J+C=700tag 1$$
Then Meghan eats $frac 45$ of the cookies, and the new total weight is $400g$. Can you then see that this means:
$$J +frac15 C = 400 tag 2$$
You now have a pair of simultaneous equations. Im sure you know how to continue this.
$endgroup$
add a comment |
$begingroup$
The problem does not seem well put with respect to the number of cookies, as long as the weight of one cookie is not given. Let
$j$ - weight of jar
$n$ - number of cookies at the beginning
$c$ - weight of one cookie
Then you have
begin{eqnarray}
j + ncdot c & = & 700 \
j + frac{n}{5}cdot c & = & 400
end{eqnarray}
$$Rightarrow frac{4}{5}cdot ncdot c = 300$$
$$Rightarrow ncdot c = frac{5}{4}cdot 300 = 375 = 3cdot 5^3$$
Restricting our consideration to integers you may have at the beginning, for example:
$125$ cookies $3g$ each
$25$ cookies $15g$ each
$15$ cookies $25g$ each- etc.
$endgroup$
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
You should assign letters to the unknown quantities and form simultaneous equations from them.
I would let the jar's weight be $J$ and the total weight of the cookies be $C$.
The first statement tells you:
$$J+C=700tag 1$$
Then Meghan eats $frac 45$ of the cookies, and the new total weight is $400g$. Can you then see that this means:
$$J +frac15 C = 400 tag 2$$
You now have a pair of simultaneous equations. Im sure you know how to continue this.
$endgroup$
add a comment |
$begingroup$
You should assign letters to the unknown quantities and form simultaneous equations from them.
I would let the jar's weight be $J$ and the total weight of the cookies be $C$.
The first statement tells you:
$$J+C=700tag 1$$
Then Meghan eats $frac 45$ of the cookies, and the new total weight is $400g$. Can you then see that this means:
$$J +frac15 C = 400 tag 2$$
You now have a pair of simultaneous equations. Im sure you know how to continue this.
$endgroup$
add a comment |
$begingroup$
You should assign letters to the unknown quantities and form simultaneous equations from them.
I would let the jar's weight be $J$ and the total weight of the cookies be $C$.
The first statement tells you:
$$J+C=700tag 1$$
Then Meghan eats $frac 45$ of the cookies, and the new total weight is $400g$. Can you then see that this means:
$$J +frac15 C = 400 tag 2$$
You now have a pair of simultaneous equations. Im sure you know how to continue this.
$endgroup$
You should assign letters to the unknown quantities and form simultaneous equations from them.
I would let the jar's weight be $J$ and the total weight of the cookies be $C$.
The first statement tells you:
$$J+C=700tag 1$$
Then Meghan eats $frac 45$ of the cookies, and the new total weight is $400g$. Can you then see that this means:
$$J +frac15 C = 400 tag 2$$
You now have a pair of simultaneous equations. Im sure you know how to continue this.
answered Jan 31 at 22:28
Rhys HughesRhys Hughes
7,0501630
7,0501630
add a comment |
add a comment |
$begingroup$
The problem does not seem well put with respect to the number of cookies, as long as the weight of one cookie is not given. Let
$j$ - weight of jar
$n$ - number of cookies at the beginning
$c$ - weight of one cookie
Then you have
begin{eqnarray}
j + ncdot c & = & 700 \
j + frac{n}{5}cdot c & = & 400
end{eqnarray}
$$Rightarrow frac{4}{5}cdot ncdot c = 300$$
$$Rightarrow ncdot c = frac{5}{4}cdot 300 = 375 = 3cdot 5^3$$
Restricting our consideration to integers you may have at the beginning, for example:
$125$ cookies $3g$ each
$25$ cookies $15g$ each
$15$ cookies $25g$ each- etc.
$endgroup$
add a comment |
$begingroup$
The problem does not seem well put with respect to the number of cookies, as long as the weight of one cookie is not given. Let
$j$ - weight of jar
$n$ - number of cookies at the beginning
$c$ - weight of one cookie
Then you have
begin{eqnarray}
j + ncdot c & = & 700 \
j + frac{n}{5}cdot c & = & 400
end{eqnarray}
$$Rightarrow frac{4}{5}cdot ncdot c = 300$$
$$Rightarrow ncdot c = frac{5}{4}cdot 300 = 375 = 3cdot 5^3$$
Restricting our consideration to integers you may have at the beginning, for example:
$125$ cookies $3g$ each
$25$ cookies $15g$ each
$15$ cookies $25g$ each- etc.
$endgroup$
add a comment |
$begingroup$
The problem does not seem well put with respect to the number of cookies, as long as the weight of one cookie is not given. Let
$j$ - weight of jar
$n$ - number of cookies at the beginning
$c$ - weight of one cookie
Then you have
begin{eqnarray}
j + ncdot c & = & 700 \
j + frac{n}{5}cdot c & = & 400
end{eqnarray}
$$Rightarrow frac{4}{5}cdot ncdot c = 300$$
$$Rightarrow ncdot c = frac{5}{4}cdot 300 = 375 = 3cdot 5^3$$
Restricting our consideration to integers you may have at the beginning, for example:
$125$ cookies $3g$ each
$25$ cookies $15g$ each
$15$ cookies $25g$ each- etc.
$endgroup$
The problem does not seem well put with respect to the number of cookies, as long as the weight of one cookie is not given. Let
$j$ - weight of jar
$n$ - number of cookies at the beginning
$c$ - weight of one cookie
Then you have
begin{eqnarray}
j + ncdot c & = & 700 \
j + frac{n}{5}cdot c & = & 400
end{eqnarray}
$$Rightarrow frac{4}{5}cdot ncdot c = 300$$
$$Rightarrow ncdot c = frac{5}{4}cdot 300 = 375 = 3cdot 5^3$$
Restricting our consideration to integers you may have at the beginning, for example:
$125$ cookies $3g$ each
$25$ cookies $15g$ each
$15$ cookies $25g$ each- etc.
answered Sep 29 '18 at 9:39
trancelocationtrancelocation
13.7k1829
13.7k1829
add a comment |
add a comment |
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1
$begingroup$
Looks a bit random and you have poor Meghan eating some of the jar. If X is the weight of the jar and Y the weight of the cookies can you write down two equations relating X and Y?
$endgroup$
– Paul
Sep 29 '18 at 7:48
1
$begingroup$
$x$ + $y$ = 700
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 7:52
1
$begingroup$
Ohh wait is it 1/5
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 7:58
2
$begingroup$
Using simultaneous equations I found out that x = 325 so the jar weighs 325g
$endgroup$
– xx_Gcsemathstudent_xx
Sep 29 '18 at 8:27
1
$begingroup$
Just a poorly worded question. There are 375g of cookies.
$endgroup$
– Paul
Sep 29 '18 at 12:08