Tutor MathsGuru: Ask me for your burning Maths questions!

[trytry]

wkong:

Dear MathsGuru,


Can you pls help for the following question and provide me the method?


A container 5/6 full of sand has a mass of 108kg. The same container ¼ full of sugar has a mass of 30kg. The container when full of sand is 60kg heavier than when it is full of sugar. Find the mass of the empty container.

Thanks.

........................{.......5/6...........}
sand :container [...][...][...][...][...] 108kg
.........................{1/4}
sugar :container [......][......][......][.....] 30kg


capacity of container same:
........................{.............10/12........}
sand :container [2u][2u ][2u][2u][2u][2u..] 108kg

.........................{3/12}
sugar :container [.3p..][..3p...][..3p..][..3p.] 30kg


Since mass of sand is 60 heavier than mass of sugar when full
===> 12u=12p+60
===> 1u=1p+5

sand: container + 10u= 108kg
sand: container + 10p + 50= 108kg

sugar: container + 3p= 30kg


therefore 7p= 108-30-50 = 28 kg
.....................1p=4kg
.....................3p=12kg
container=30kg-12kg=18kg
try mine best

[Jolyn]

Maths Monster:

Jolyn:

[quote=\"Guan Hui\"]hi jolyn,


1)
when you transfer 30 books from box to shelf.
box will minus 30 books while shelf increase 30 books.
originally there were 84 more books on the shelf than box.
so... 84 +30+30=144 more books on shelf than in box now.

2)
514 face towels 312 hand towels
total = 514+312=826 towels
Total towels sold =1982
Number of bath towel=1982-826=1156
how many more? 1156-514=642 towels more

Hi Guan Hui

Thanks for your answer but I do not understand as follows:

1. Why it is 84+30+30 and not 84+30-30? As box minus 30 and shelf increase 30....

Thks
Jolyn

Hope this model helps:


http://www.postimage.org/image.php?v=aVDVHPr[/quote]Thks for the explained model.

[Jolyn]

david59:

Jolyn:

[quote=\"Guan Hui\"]hi jolyn,


1)
when you transfer 30 books from box to shelf.
box will minus 30 books while shelf increase 30 books.
originally there were 84 more books on the shelf than box.
so... 84 +30+30=144 more books on shelf than in box now.

2)
514 face towels 312 hand towels
total = 514+312=826 towels
Total towels sold =1982
Number of bath towel=1982-826=1156
how many more? 1156-514=642 towels more

Hi Guan Hui

Thanks for your answer but I do not understand as follows:

1. Why it is 84+30+30 and not 84+30-30? As box minus 30 and shelf increase 30....

Thks
Jolyn

The reason is easier to see in the model method.

http://www.postimage.org/image.php?v=gxlAgyS[/quote]It is easier to see in your model method.

Thks....

[Vanilla Cake]

Hi small/adhdadhd/Maths Monster,

Thanks for your helpful/clear/useful explanations.

BTW, Maths Monster, your nick is cute :politebleah: and it's difficult to imagine how a Maths Monster looks like.

Hi Chief/Mods,
Could you pls consider to have a new emoticon :idea: to express that the thread starter would like his/her problem sum/s to be answered with Maths model solutions instead of typing out like my http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=6373&postdays=0&postorder=asc&start=940 on 24 Apr 2010 17:30 to let the readers know?
Something like this :lovesite: with text such as \"Love to have model solutions\".

Thanks in advance for your kind consideration.
Have a great Sunday.
:celebrate:

[Daddy]

Dear MathsGuru,


Please help P5 math question.

1. The area of the rectangle ABCD below is 140 cm2.
Area of triangle XYD is 20 cm2.
Find the total shaded area of the rectangle.

http://i222.photobucket.com/albums/dd39/tham33/A.jpg\">

Daddy
Thanks all

[Maths Monster]

delete

[Maths Monster]

delete

[Maths Monster]

delete

[small]

Daddy:

Dear MathsGuru,


Please help P5 math question.

1. The area of the rectangle ABCD below is 140 cm2.
Area of triangle XYD is 20 cm2.
Find the total shaded area of the rectangle.

http://i222.photobucket.com/albums/dd39/tham33/A.jpg\">

Daddy
Thanks all

Hi daddy,

Please find the solution.

http://www.postimage.org/image.php?v=Tsg9A3i

[Dharma]

Daddy:

Dear MathsGuru,


Please help P5 math question.

1. The area of the rectangle ABCD below is 140 cm2.
Area of triangle XYD is 20 cm2.
Find the total shaded area of the rectangle.

http://i222.photobucket.com/albums/dd39/tham33/A.jpg\">

Daddy
Thanks all

Hi Daddy


The area of 3 shaded triangles + area of XYD = 1/2 of area of ABCD
Shaded area = (1/2 x 140cm2) - 20cm2 = 50cm2