Q&A - PSLE Math

[Chan09]

Need some help on this:

A has $900 more than B. A gave B some money. In the end B had $800 more than A. How much did A give B?
Tried model diagram but difficult to visualise? Tks

[superksmum]

Hi need help on 2011 Roysth paper 2, question number 12.


Four children Min, Nathan, Tom and Caleb each have some savings. The amount of money Nathan has is 1/3 of the total amount of money Tom, Min and Caleb have. The amount of money Tom has is 1/4 of the total amount of money Nathan, Min and Caleb have. The amount of money Min has is 1/5 of the total amount of money Nathan, Tom and Caleb have. If Caleb saves $1035, how much do the four children have altoghether?

Thank you.

[tianzhu]

superksmum:

Hi need help on 2011 Roysth paper 2, question number 12.


Four children Min, Nathan, Tom and Caleb each have some savings. The amount of money Nathan has is 1/3 of the total amount of money Tom, Min and Caleb have. The amount of money Tom has is 1/4 of the total amount of money Nathan, Min and Caleb have. The amount of money Min has is 1/5 of the total amount of money Nathan, Tom and Caleb have. If Caleb saves $1035, how much do the four children have altoghether?

Thank you.

Hi

This question has been discussed before.

The total amount of money in the three scenarios is the same. Make the total number of units the same.

A common multiple of 4, 5 and 6 is 60.

Nat : (Tom + Min + Caleb) ------ 1:3 ((4) ------ 15:45 (60)
Tom : (Nat + Min + Caleb) ------ 1:4 (5) ------ 12:48 (60)
Min : (Nat + Tom + Caleb) ------ 1:5 (6) ------ 10:50 (60)

Nat ------ 15 units
Tom ------ 12 units
Min ------- 10 units
Caleb ------ 23 units

23 units ------ 1035
1 unit ------ 45

60*45 ------ 2700

Best wishes

[superksmum]

tianzhu:

superksmum:

Hi need help on 2011 Roysth paper 2, question number 12.


Four children Min, Nathan, Tom and Caleb each have some savings. The amount of money Nathan has is 1/3 of the total amount of money Tom, Min and Caleb have. The amount of money Tom has is 1/4 of the total amount of money Nathan, Min and Caleb have. The amount of money Min has is 1/5 of the total amount of money Nathan, Tom and Caleb have. If Caleb saves $1035, how much do the four children have altoghether?

Thank you.

Hi

This question has been discussed before.

The total amount of money in the three scenarios is the same. Make the total number of units the same.

A common multiple of 4, 5 and 6 is 60.

Nat : (Tom + Min + Caleb) ------ 1:3 ((4) ------ 15:45 (60)
Tom : (Nat + Min + Caleb) ------ 1:4 (5) ------ 12:48 (60)
Min : (Nat + Tom + Caleb) ------ 1:5 (6) ------ 10:50 (60)

Nat ------ 15 units
Tom ------ 12 units
Min ------- 10 units
Caleb ------ 23 units

23 units ------ 1035
1 unit ------ 45

60*45 ------ 2700

Best wishes

Hi Tianzhu,

Thank you for your quick response.
I also recall seeing this question, but just unable to find the page discussed.

Cheers

[Mr OK]

Hello everyone, I’m new to this forum. Would appreciate some help for these questions:-


1) Mr Lau sells notebooks at $2 each and files at $3 each. After he sold 100 notebooks and files, the amount he collected from the sale of notebooks was $60 more than than the amount collected from the sale of files. How many notebooks did Mr Lau sell?

2) There are some blue chips and red chips in a bag. If 2 blue chips are removed from the bag, the number of blue chips will be 1/6 of the total number of chips left.
If 4 red chips are removed from the bag, the number of blue chips will be 1/4 of the total number of chips left. How many chips are there in the bag?

3) Sally had 20 more books than Ali. After Sally gave 15 of her books to Ali, Sally’s remaining number of books was 3/8 of their total number of books.
A) How many books did Ali have at first?
B) What is the difference in the number of books they finally had?

[tianzhu]

Chan09:

Need some help on this:

A has $900 more than B. A gave B some money. In the end B had $800 more than A. How much did A give B?
Tried model diagram but difficult to visualise? Tks

Hi

This question looks easy at first glance as it contains not too much information.However,it might be tricky.

A gave B 850.

Picture A with 1900 and B with 1000 at first.

The amount of money before and after stayed the same. Perhaps this might help you to draw the MD.

Best wishes

[tianzhu]

homeworkmummy:

Hi, can someone help me with St Nicks 2011 P6 SA1 paper Q26. Can't upload the document as I don't have a scanner.....appreciate it.

Hi

Q26 on page 13

http://www.orlesson.org/orp/11Ma/2011-P6-Math-SA1-StNics.pdf

X,Y and Z shared the shaded part.

Z (shaded) -------- 3
Z (unshaded) -------- 5

X (shaded) -------- 3
X (unshaded) -------- 9

Y (shaded) -------- 3
Y (unshaded) -------- 12

Shaded area of Y : total area of figure ------- 3:29 (3+5+9+12)

Best wishes

[homeworkmummy]

tianzhu:

homeworkmummy:

Hi, can someone help me with St Nicks 2011 P6 SA1 paper Q26. Can't upload the document as I don't have a scanner.....appreciate it.

Hi

Q26 on page 13

http://www.orlesson.org/orp/11Ma/2011-P6-Math-SA1-StNics.pdf

X,Y and Z shared the shaded part.

Z (shaded) -------- 3
Z (unshaded) -------- 5

X (shaded) -------- 3
X (unshaded) -------- 9

Y (shaded) -------- 3
Y (unshaded) -------- 12

Shaded area of Y : total area of figure ------- 3:29 (3+5+9+12)

Best wishes

Thanks Tianzhu for the help!

[kklau]

Hi,

Appreciate anyone's help for this question.

The diagram, not drawn to scale, shows two similar triangles and quadrants. Find the area of the shaded part.

http://i48.tinypic.com/9vi2ir.jpg\">

Thank you!

[MathIzzzFun]

Mr OK:

Hello everyone, I'm new to this forum. Would appreciate some help for these questions:-


1) Mr Lau sells notebooks at $2 each and files at $3 each. After he sold 100 notebooks and files, the amount he collected from the sale of notebooks was $60 more than than the amount collected from the sale of files. How many notebooks did Mr Lau sell?

Hi

supposition or assumptive method, using area model...

http://i46.tinypic.com/n4bf5s.png\">

cheers.