Q&A - PSLE Math

[mistychances]

Sorry Moderator Will watch out the next time.


Thank you very much Math Izzz Fun Now I get the picture

[2632parent]

Sorry class monitor, I will be more careful in future. :imsorry:

[nounou]

Kindly include explanation as well. Can't understand the working :gloomy: :stupid: :imdrowning: :imsorry:


Many thanks X 100000000000000 :?:
:thankyou:
:salute:

tianzhu:

Treelodge:

Dear Tianzhu, HELP please! :?:

:? I don't understand \"Hence, 1 unit of bookmark ------- 12/6 ------- 2
1 unit of bookmarks ------- 8
There is an extra of 6 (8-2) because the bookma
rk costs 30 cents more than a sticker.
Number of bookmarks ------- 600/30 ------ 20
Therefore cost of 1 bookmark -------- 800/20 ------- 40 cents.\"

Hi

I am sorry for the error.

It should be read as 1 unit of stickers instead of bookmarks.

I'll revise the original post.

Please draw out the MD as it gives a clearer picture.

Best wishes

[tianzhu]

Treelodge:

Kindly include explanation as well. Can't understand the working :gloomy: :stupid: :imdrowning: :imsorry:

Many thanks X 100000000000000 :?:
:thankyou:
:salute:

Hi

Good Morning.

My earlier response to anneshirleygilbert’s question was an attempt to break down the question for her to draw out the MD.

I’ll attempt to further break down the question into smaller parts.

Betina spent $20 on some stickers and bookmarks. She spent $4 more on the stickers than on the bookmarks.

This gives us,

Amount spent on stickers ------ 12
Amount spent on bookmarks ------- 8

Please draw the MD.

She bought 6 times as many stickers as bookmarks.

Bookmarks ------ 1 box
Stickers ------- 6 boxes

The amount spent on stickers is shown by 6 boxes.

Hence, 1 box of stickers ------- 12/6 ------- 2

The amount spent on bookmarks is shown by 1 box + an amount equal to (8 – 2).

There is an extra of 6 (8-2) because the bookmark costs 30 cents more than a sticker.

From here, we are able to calculate the number of bookmarks.

Number of bookmarks ------- 600/30 ------ 20

Therefore cost of 1 bookmark -------- 800/20 ------- 40 cents.

Best wishes

[mistychances]

4 girls share 2 identical butter cakes equally.

5 boys share 4 identical butter cakes equally.
What is the difference between each boy's and each girl's share?

1) 1/5
2) 1/4
3) 3/10
4) 1/2

I keep getting 1.1/2

Thank You

** Hopefully I've posted in the right place this time round **

[MathIzzzFun]

mistychances:

4 girls share 2 identical butter cakes equally.

5 boys share 4 identical butter cakes equally.
What is the difference between each boy's and each girl's share?

1) 1/5
2) 1/4
3) 3/10
4) 1/2

I keep getting 1.1/2

Thank You

** Hopefully I've posted in the right place this time round **

Hi

each girl --> 2/4 = 1/2 cake
each boy --> 4/5 cake
.. can you work out the difference.\\?

cheers.

[jewelbox]

Hi, how do i solve this qn? thanks.

The ratio of the 3 sides of a right-angled triangle is 3:4:5. if the area of the triangle is 150 cubic cm, what is its perimeter?

[tianzhu]

jewelbox:

Hi, how do i solve this qn? thanks.

The ratio of the 3 sides of a right-angled triangle is 3:4:5. if the area of the triangle is 150 cubic cm, what is its perimeter?

Hi

Similar triangles are not covered in primary school maths syllabus.

So, I think a suitable way is \"Systematic Listing”.

It’s not too tedious in this case.

Ratio of 3 sides ------- 3:4:5

Use equivalent ratios, do a listing

Ratio of 3 sides ------- 15:20:25

This gives an area of 150 sq cm.

Hence, the perimeter is 60 cm

Best wishes

[mistychances]

Thank You, MathIzzzFun. Now, I know my mistake. Should hv just left them as fraction.


I’ve got another one here:

Question:
At first Alvin had twice as many trading cards as Steven. After Alvin had given away 285 of his trading cards, Steven had twice as many trading cards as Alvin. How many trading cards did they have altogether at first?

My working:
At first let Alvin -> 4u, so Steven will be 2u (altogether 6u at first)
After -> Alvin-1u, Steven-2u, so 285=3u
1u=285/3=95
Total 6u=570 –>My answer.

But the answer given was 845.

Appreciate your help once again.

[tianzhu]

mistychances:

But the answer given was 845.

Hi

Your answer of 570 is correct.

Best wishes