Tutor MathsGuru: Ask me for your burning Maths questions!

[chl72]

Hi!


Need some help with this question

4/5 of substance X has the same mass as 2/7 of substance Y. What fraction of substance X is equal in mass to 2/3 substance Y?

TIA!

[mrswongtuition]

CJM:

Alex spent 3/8 of his money while Alice spent 3/5 of her money in a carnival. They found that they have the same amount of money at the end of the carnival. After counting their money, they had a total of $725 left. How much money did Alex spend at the carnival?

Alex spent 3/8 of his money which means that he has 5/8 left.
Alice spent 3/5 of her money which means that she has 2/5 left.

Since they have the same amount at the end...
Alex`[_][_][_][_][_]`}Total Left:
Alice [-------][-------] } $725

5 units of Alex = 2 units of Alice
Multiply to make them the same.
5 x 2 units of Alex = 2 x 5 units of Alice

Total 20units left -> $725

Since Alex had 8 x 2 units = 16 units at first,
it means that he spent 6 units.

1 unit -> $36.25
6 units -> $217.50

[mrswongtuition]

chl72:

Hi!


Need some help with this question

4/5 of substance X has the same mass as 2/7 of substance Y. What fraction of substance X is equal in mass to 2/3 substance Y?

TIA!

Almost the same as the above question.

X [-][-][-][-]
Y [= =][= =]

4 units of X = 2 units of Y
Multiply to make them the same:
4 x 1 units of X = 2 x 2 units of Y
4 units of X = 4 units of Y

X will have a total of 5 units,
Y will have a total of 7 x 2 = 14 units.

2/3 of 14 units = 9 & 1/3 units

To make the numbers into whole numbers so that it's easier to compare,
X will have 15 units,
Y will have 42 units.

2/3 of 42 units = 28 units

28/15 = 1 & 13/15 of X is the same as 2/3 of Y

[chl72]

mrswongtuition:

chl72:

Hi!


Need some help with this question

4/5 of substance X has the same mass as 2/7 of substance Y. What fraction of substance X is equal in mass to 2/3 substance Y?

TIA!

To make the numbers into whole numbers so that it's easier to compare,
X will have 15 units,
Y will have 42 units.

2/3 of 42 units = 28 units

28/15 = 1 & 13/15 of X is the same as 2/3 of Y

Thank you for your fast response, Mrs Wong!

I worked till X=15U and Y=42U, and got confused.. :oops:
The answer key gave 5/21 as answer, simply cannot understand how to get this answer. Pls help! Thanks a million!

[CJM]

mrswongtuition:

CJM:

Alex spent 3/8 of his money while Alice spent 3/5 of her money in a carnival. They found that they have the same amount of money at the end of the carnival. After counting their money, they had a total of $725 left. How much money did Alex spend at the carnival?

Alex spent 3/8 of his money which means that he has 5/8 left.
Alice spent 3/5 of her money which means that she has 2/5 left.

Since they have the same amount at the end...
Alex`[_][_][_][_][_]`}Total Left:
Alice [-------][-------] } $725

5 units of Alex = 2 units of Alice
Multiply to make them the same.
5 x 2 units of Alex = 2 x 5 units of Alice

Total 20units left -> $725

Since Alex had 8 x 2 units = 16 units at first,
it means that he spent 6 units.

1 unit -> $36.25
6 units -> $217.50

thank u so much : )

[tinasen]

Dear Maths Guru,


I badly need help to solve this homework problem for my son.

A basket with 65 sweets has a mass of 3200g. The same basket with 40 sweets has a mass of 2125g. Each sweet has the same mass. What is the mass of the basket.

Your help is greatly appreciated.
Thanks
Tinasen

[Eddow]

basket + 65 sweets = 3200

basket _ 40 sweets = 2125

So if you take 3200- 2125 = 1075, the result will be for the 25 sweets
then, 1 sweet will be 1075 divide by 25 = 43g

take 43 x 40 sweets =1720g
2125 - 1720 = 405g (mass of basket)

[tinasen]

Eddow:

Hi Eddow,

Just a doubt. Doesn't 1720g include the basket mass as well.

- tinasen

basket + 65 sweets = 3200
basket _ 40 sweets = 2125

So if you take 3200- 2125 = 1075, the result will be for the 25 sweets
then, 1 sweet will be 1075 divide by 25 = 43g

take 43 x 40 sweets =1720g
2125 - 1720 = 405g (mass of basket)

[tinasen]

Sorry… Haven’t used the forum so started this as new topic instead of posting it in this forum. Now have re-posted my question here. Sorry for the inconvenience.


Dear Maths Guru,

I badly need help to solve this homework problem for my son.

A basket with 65 sweets has a mass of 3200g. The same basket with 40 sweets has a mass of 2125g. Each sweet has the same mass. What is the mass of the basket.

Your help is greatly appreciated.
Thanks
Tinasen

[Brenda10]

tinasen:

Sorry.. Haven't used the forum so started this as new topic instead of posting it in this forum. Now have re-posted my question here. Sorry for the inconvenience.


Dear Maths Guru,

I badly need help to solve this homework problem for my son.

A basket with 65 sweets has a mass of 3200g. The same basket with 40 sweets has a mass of 2125g. Each sweet has the same mass. What is the mass of the basket.

Your help is greatly appreciated.
Thanks
Tinasen

Hi, I'm not mathsguru but hope the following working can help:

3200g - 2125g = 1075g (To find out the mass of 25 sweets)
1075g / 25 = 43g (Mass of one sweet)
2125g - (40 x 43g) = 405g

Hence, the mass of the basket is 405g.