Q&A - PSLE Math

[Herbie]

Q2


Apple : watermelon
1u : 2u
-8
-----------
3p : 5 p

Hence
1u = 3p… Eq 1
2u~8=5p… Eq 2

Sub eq 1 into eq 2

P=8, u=24

no. Of apples =24, no. Of watermelon =48

[Herbie]

Q 1.


a. 27+8=35
b. 6:12:8

[BlueBells]

Here’s one question. I can’t remember the exact wordings, but it goes something like this:


In a hall, if the chairs are arranged 13 in a row, there are 6 in excess. If they are arranged 17 in a row, there are 4 chairs short. If there are between 200 - 300 particpants for the event, how many chairs are there?

Thanks for any enlightenment.

[MathIzzzFun]

ReturnedSingaporean:

I am having problem trying to help my girl with this question. Please help if possible. Thanks very much


Question :
(1) Samantha stacked some identical white cubes together to form a larger cube. All the 6 faces of the larger cube were then painted blue. 8 of the smaller cubes did not have any blue face
(a) what is the total number of white cubes ?
(b) Find the ratio of the number of cubes with one blue face to the number of cubes with 2 blue faces to the number of cubes with 3 blue faces


(2) John bought some fruits. 1/3 of them are apples and the rest were watermelons. If he gives away 8 watermelons, there will be 3/5 as many apples as watermelons. How many apples and watermelons were there in the basket at first.

Look forward to any assistance to the above questions

Hi

Q1.
when the larger cube is painted, all the outer surfaces will be painted --> which means that the outer 1 layer of cubes will be painted on 1 side, 2 sides or 3 sides. The only cubes that will not be painted are those \"inside\". Since 8 cubes are not painted --> a \"medium\" cube with 2 cubes on each side. So, the larger cube is made of 4 cubes on each side --> 4 x 4 x4 = 64 cubes in all.

Number of cubes with 1 side painted : 2 sides painted : 3 sides painted
= 24 : 24 : 8
= 3 : 3 : 1


Q2.
Another approach -- note that number of apples remain the same, so
At first, apples : watermelons --> 1 : 2 --> 3u : 6u
In the end, apples : watermelons --> 3u : 5u

1u --> 8

At first, apples --> 3 x 6 = 18, watermelons --> 6 x 8 = 48



cheers.

[mumworks]

Hi,


How to explain to the kid this type of qs ?

In a group of 9 pupils, there are 4 boys.
Mr Tan wants to pair off each girl with a boy for a project.
How many different ways can he pair off a boy with a girl ?

Thank you very much.

[Nebbermind]

mumworks:

Hi,


How to explain to the kid this type of qs ?

In a group of 9 pupils, there are 4 boys.
Mr Tan wants to pair off each girl with a boy for a project.
How many different ways can he pair off a boy with a girl ?

Thank you very much.

it looks somewhat like GEP or MO qn!!

I 'revised' for psle some yrs ago...never came across this type of qn.

[imacsg]

Ai Tong CA1 Q14


Can someone help me?
Amy savings was 40% less than Baoyu’s saving at first. After Amy donated $52 and Baoyu donated $60, Baoyu’s savings became 5 times as much as Amy. What was their total savings at first?

Which of the following is the best estimate of 55 x 249?
Ans is 50 x 250. But why not 60 x 200?
1. 50 x 200
2. 50 x 250
3. 60 x 200
4. 60 x 250

Thanks.

[2DMommy]

My boy’s homework, appreciate your help.


1) Andrew had some red apples and green apples to sell 3/5 of them were red apples and the rest were green apples. After he sold of 5/6 the red apples and 100 green apples, he had 1/4 of the apples left. How many apples did he have altogether at first ?

2) Harry shared his money with Rosa in the ratio 9:7. When Harry spent $67.50 and Rosa spent $90, the new ratio of his money to Rosa’s money became 9:4.
a) How much did Rosa have left ?
b) How much did Harry Have at first ?

Thank you !

[tianzhu]

2DMommy:

2) Harry shared his money with Rosa in the ratio 9:7. When Harry spent $67.50 and Rosa spent $90, the new ratio of his money to Rosa's money became 9:4.
a) How much did Rosa have left ?
b) How much did Harry Have at first ?

Hi

You may use \"Units and Parts\"

At first
Harry: Rosa ------- 9u:7u

Change
Harry: Rosa ------- -67.50:-90

In the end
Harry: Rosa ------- 9p:4p

Equalise the parts.

(9u – 67.5) ----- 9p
(x4)
36u - 270 ------ 36p

(7u - 90) ----- 4p
(x9)
63u - 810 ------36p

36u - 270 ----- 63u - 810
27u ------ 540
u ------ 20

Amount of money Rosa left ------ (7*20) - 90 ------ 50

Amount of money Harry had at first ------- 9*20 ------ 180

Best wishes

[shurley197323]

Hi,pls help. I got 3 qtns from Aitong CA 1paper.


1) In a boutique,the no of dresses sold was 70.This was 40% more than the no of blouses sold. How many blouses were sold
My answer is 42, Paper answer is 50

2) X,Y & Z bought a watch for their mum. X paid 1/4 of what Y & Z paid. Y paid 1/5 of what X and Z paid. If Z paid $56 more than Y, how much did the watch cost.
Answer :$120

3)Amy saving was 40% less than baoyu at first. After Amy donated $52 and baoyu donated $60. Baoyu saving becomes 5 times as much as AMy. What was their saving at first?
Answer : $160.

Thanks in advance.