Q&A - PSLE Math

[Zhu99]

Shimmer:

One more question pls!


Dean,Ellen and Andy shared a box of sweets in the ratio of 3:4:5 and there was 4 left .They put the 4 sweets into a second box which contained 1/8 fewer sweets than the first box, and shared the sweets in the same ratio as before,and this time there were no remainder.
A)Find the total number of sweets they shared in the first round.
B)Find the total number of sweets each child received in both rounds of sharing.

3 + 4 + 5 = 12

Multiple of 12 ---- 12 , 24 , 36 , 48 , 60 , .... 1st round
Add 4 ------------- 16 , 28 , 40 , 52 , 64 , .......
Multiply by 7/8 --- 14 , X , 35 , X , 56 , ......
Add 4 ------------- 18 , X , 39 , X , 60 , ....... 2nd round
60 is divisible by 12.

a) Total number of sweets they shared in first round is 60 (excludes the remainder 4).

12 u ---> 60 + 60 = 120
1 u ---> 120/12 = 10

3 u ---> 10 x 3= 30
4 u ---> 10 x 4 = 40
5 u ---> 10 x 5 = 50

b) The total number of sweets Dean, Allen, Ellen and Alan received in both rounds are 30, 40 and 50.

[MathIzzzFun]

student101:

I tried different way to solve below problem for last couple of days. Pls help me as I feel very difficult to get the solution:


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

http://i45.tinypic.com/166dxdh.png\">

cheers.

[tianzhu]

maychang:

I'm trying to upload a image. As the instruction for upload a file and click the Add To Post button to add it to your post, however i couldn't find the \"Add to Post\" button in the screen.


Anyone has the same issue?

Hi

There are rectangles boxes at the top when you click on \"post reply or new topic\".

To insert images, use \"Img\"

Best wishes

[tianzhu]

lesskiasu:

Hi, can anyone help on to this question? The question is Catholic High Prelim 2011. http://i45.tinypic.com/2ryfq6o.jpg\">

Hi

Students are requested to leave their answers in terms of pi.

Apply the formula for calculating the area of a semi circle, and you should get an answer of 12.5pi.

Best wishes

[fathima]

How to do overlapping sums Primary 6 child for PSLE ?

[fathima]

6 / 2 = 3

1/2 X pi X 3 X 3 = 4.5 pi
8 / 2 = 4
1/2 X pi X 4 X 4 = 8 pi
8 pi + 4.5 pi = 12.5 p


ANSWER: 12.5 pi cm2

[lesskiasu]

tianzhu:

lesskiasu:

Hi, can anyone help on to this question? The question is Catholic High Prelim 2011. http://i45.tinypic.com/2ryfq6o.jpg\">

Hi

Students are requested to leave their answers in terms of pi.

Apply the formula for calculating the area of a semi circle, and you should get an answer of 12.5pi.

Best wishes

Thanks Tianzhu for the answer. My dd couldn't figure out the working thus no answer for this.
Will get her do it next time to post the question together with the answer.
:thankyou:

[peggy]

Kindly assist.



A number of passengers boarded an empty MRT train at pasir ris station.

At Tampines station, 2/5 of them alighted and 80 boarded the train.
At Simei station, 223 alighted and 38 boarded the train.
The train now has 3/8 of the number of passengers when it left Tampines station.

A. How many passengers were on the train when it left Simei station?
B. How many passengers were on the train when it left Pasir Ris station?

Thank you.

[zanen]

hello can help me with Peichun prelim 2012 qn 15 on circles? my laptop cannot upload photo. thanks

[MathIzzzFun]

zanen:

hello can help me with Peichun prelim 2012 qn 15 on circles? my laptop cannot upload photo. thanks

http://tinyurl.com/mathizzzfun-PeiChun-2012Prelim


cheers.