Q&A - PSLE Math

[small]

:thankyou: so much MathIzzzFun.


So the answer is 28 sweets.

[MathIzzzFun]

small:

:thankyou: so much MathIzzzFun.


So the answer is 28 sweets.

good morning, small... that's correct


cheers.

[tech_nomax]

MathIzzzFun:

tech_nomax:

At Station A, the ratio of the number of children to the number of adults on a train was 4:5. At the next station, 12 children alighted and 10 adults boarded the train. The ratio of the number of children to the number of adults on the train then became 7:10. How many children were on the train at first?

Hi

At first, Children : Adults --> 8u : 10u
In the end, Children : Adults --> 7u + 7 : 10u + 10
So, 8u - 12 = 7u +7
1u --> 19

Children, at first --> 8 x 19 = 152

cheers.

:thankyou: very much MathIzzzFun!

could you please let me know in line two, why to write
In the end, Children : Adults --> \"7u + 7 : 10u + 10\", instead of \"7u : 10u\".

Thanks in advance.

[brastilava]

Hi, please assist in this problem (sorry, not sure how to attach image):


The figure shows two quadrants. Find length AB.

http://i47.tinypic.com/xclyyr.jpg

[Nebbermind]

brastilava:

Hi, please assist in this problem (sorry, not sure how to attach image):


The figure shows two quadrants. Find length AB.

http://i47.tinypic.com/xclyyr.jpg

When u extend the smaller quartrant to become a semi-circle overlapping the bigger quartrant, u will see the answer.

[brastilava]

Hi Nebbermind, I see it! Thanks so much:)

[MathIzzzFun]

tech_nomax:

MathIzzzFun:

[quote=\"tech_nomax\"]At Station A, the ratio of the number of children to the number of adults on a train was 4:5. At the next station, 12 children alighted and 10 adults boarded the train. The ratio of the number of children to the number of adults on the train then became 7:10. How many children were on the train at first?

Hi

At first, Children : Adults --> 8u : 10u
In the end, Children : Adults --> 7u + 7 : 10u + 10
So, 8u - 12 = 7u +7
1u --> 19

Children, at first --> 8 x 19 = 152

cheers.

:thankyou: very much MathIzzzFun!

could you please let me know in line two, why to write
In the end, Children : Adults --> \"7u + 7 : 10u + 10\", instead of \"7u : 10u\".

Thanks in advance.[/quote]Hi

It is easier to see with a MD, so try drawing the model.
in the end,
10 adults boarded, so
total number of adults --> 10u + 10 = 10 x (1u + 1)
Since in the end, ratio of children : adults = 7 : 10
children --> 7 x (1u + 1) = 7u + 7

here's the MD...

http://i49.tinypic.com/jph1jr.png\">

cheers.

[brastilava]

Hi, please help in this question:


The figure below is made up of three triangles A, B, and C.
50% of Triangle A is shaded. 1/4 of Triangle B is shaded. 20% of Triangle C is shaded. The total area of Triangle A and Triangle B is 125% of the area of Triangle C. Express the area of Triangle A as a fraction of the area of Triangle B. Leave your answer in its simplest form.

http://i49.tinypic.com/ok7a7k.jpg

[MathIzzzFun]

brastilava:

Hi, please help in this question:


The figure below is made up of three triangles A, B, and C.
50% of Triangle A is shaded. 1/4 of Triangle B is shaded. 20% of Triangle C is shaded. The total area of Triangle A and Triangle B is 125% of the area of Triangle C. Express the area of Triangle A as a fraction of the area of Triangle B. Leave your answer in its simplest form.

http://i49.tinypic.com/ok7a7k.jpg

Hi

this was posted some time ago - http://www.flickr.com/photos/62167097@N02/6705370185/in/set-72157629872038060

cheers.

[tianzhu]

brastilava:

Hi, please help in this question:


The figure below is made up of three triangles A, B, and C.
50% of Triangle A is shaded. 1/4 of Triangle B is shaded. 20% of Triangle C is shaded. The total area of Triangle A and Triangle B is 125% of the area of Triangle C. Express the area of Triangle A as a fraction of the area of Triangle B. Leave your answer in its simplest form.

http://i49.tinypic.com/ok7a7k.jpg

Hi

A similar question has been discussed before.

Hope this helps.

Best wishes

http://farm8.staticflickr.com/7161/6707675849_d6e9dec552_z.jpg\">