Q&A - PSLE Math

[ivanhoo99]

Belle2011:

Dear all,

I need some help on this problem.

At a fitness carnival, 1600 people participated in a Mass Dance and Taiji. 30% of the 1300 Mass Dance participants were adults. 40% of the Taiji participants were children. During the break, some Mass Dance participants went on to participate in Taiji, while some Taiji participants went on to participate in the Mass Dance. After the change, 25% of the Mass Dance participants and 75% of the Taiji participants were adults. How many Mass Dance participants were there after the change?

model answer: 1260

Thank-you.

Cheers,
Belle.

May i know which book you had taken from? Im also troubled by the question as i dunno how to do. Thx!!!

[ivanhoo99]

ksi:

bobsg01:

Pri. 6 Vol. of Liquids question.


Thanks for helping. :scratchhead:

http://i54.tinypic.com/15ez0pg.jpg\">

Assuming p6 knows cube root?
Then it is easy, cube root of 216 = 6
Hence the l x b x h = 6 x 6 x 6 for container A.

If container B has the same height and breadth as container A, then to fill half of the tank = 15.4 x 6 x 3 = 277.2 cubic cm

Is the Ans suppose to be 61.2? Because they ask for how much MORE water is needed to fill half of it.

[MathIzzzFun]

Belle2011:

Dear all,

I need some help on this problem.

At a fitness carnival, 1600 people participated in a Mass Dance and Taiji. 30% of the 1300 Mass Dance participants were adults. 40% of the Taiji participants were children. During the break, some Mass Dance participants went on to participate in Taiji, while some Taiji participants went on to participate in the Mass Dance. After the change, 25% of the Mass Dance participants and 75% of the Taiji participants were adults. How many Mass Dance participants were there after the change?

model answer: 1260

Thank-you.

Cheers,
Belle.

hi

http://i53.tinypic.com/1zbw0f6.jpg\">

cheers.

[corneyAmber]

ivanhoo99:

ksi:

[quote=\"bobsg01\"]Pri. 6 Vol. of Liquids question.


Thanks for helping. :scratchhead:

http://i54.tinypic.com/15ez0pg.jpg\">

Assuming p6 knows cube root?
Then it is easy, cube root of 216 = 6
Hence the l x b x h = 6 x 6 x 6 for container A.

If container B has the same height and breadth as container A, then to fill half of the tank = 15.4 x 6 x 3 = 277.2 cubic cm

Is the Ans suppose to be 61.2? Because they ask for how much MORE water is needed to fill half of it.[/quote]
Sorry I misread. yes 216 cubic cm of water is already inside the container B, so to make it half-filled, must take 277.2-216 = 61.2 cubic cm.

[chrisu]

Hi need help for this question;


The figure below, not drawn to scale, shows 2 semi-circles and a right-angled triangle overlapping one another. The diameter of the smaller semi-circle is half of the bigger semi-circle. Find the area of the shaded part given that the diameter of the bigger semi-circle is 40cm.
Give your answer correct to 2 decimal places.

http://img.photobucket.com/albums/v160/guppiesonli/Misc/Q18.jpg\">

[PiggyLalala]

chrisu:

Hi need help for this question;


The figure below, not drawn to scale, shows 2 semi-circles and a right-angled triangle overlapping one another. The diameter of the smaller semi-circle is half of the bigger semi-circle. Find the area of the shaded part given that the diameter of the bigger semi-circle is 40cm.
Give your answer correct to 2 decimal places.

http://img.photobucket.com/albums/v160/guppiesonli/Misc/Q18.jpg\">

area of shaded area = area of big semicircle + area of small semicircle - area of triangle
= 0.5 X3.142 X 20 X 20 + 0.5 X3.142 X 10 X 10 - 1/2 X 20 X 40 ( use the calculator pie)
=385.40 cm square

[chrisu]

Thank you, didn't realise it's just so straight forward. Makes my day.

PiggyLalala:

chrisu:

Hi need help for this question;

The figure below, not drawn to scale, shows 2 semi-circles and a right-angled triangle overlapping one another. The diameter of the smaller semi-circle is half of the bigger semi-circle. Find the area of the shaded part given that the diameter of the bigger semi-circle is 40cm.
Give your answer correct to 2 decimal places.

http://img.photobucket.com/albums/v160/guppiesonli/Misc/Q18.jpg\">

area of shaded area = area of big semicircle + area of small semicircle - area of triangle
= 0.5 X3.142 X 20 X 20 + 0.5 X3.142 X 10 X 10 - 1/2 X 20 X 40 ( use the calculator pie)
=385.40 cm square

[tianzhu]

ivanhoo99:

May i know which book you had taken from? Im also troubled by the question as i dunno how to do. Thx!!!

Hi

This question is from Singapore Chinese Girls' School (Primary) P6 Prelim 2010 Paper 2 Q17.

Please go to page 22 of this link.

http://www.orlesson.org/orp/10Ma/2010-P6-Math-SA2-SCGS.pdf

Best wishes

[Belle2011]

Dear tianzhu and MathIzzzFun,

Thank-you for sharing your solutions.

Cheers,
Belle.

[bobsg01]

10q to ksi and ivanhoo99 for the answers.


:celebrate: :hi5: