Q&A - PSLE Math

[happyheart]

Hi,

pls help with this question. Thanks!

Andy, Brad, Colin shared money to buya present for their teacher. The ratio of the amount of money contributed by Andy to the total amount contributed by Brad, Colin and Dominic was 1:5. Brad contributed 1/11as much as the total contributed by Dominic. If Andy contributed $2.10 more than Brad, how much did Dominic contribute?

[happyheart]

Hi, one more please. I am always confused when there is transfer back and forth.Thanks.


Jack and Aqil had some game cards. If Jack gave Aqil 52 cards, he would have the same number of cards as Aqil. If Aqil gave Jack 34 cards, the ratio of the number of cards Aqil had to the number of cards Jack had would be 3:7.How many cards did Jack have at first?

[MathIzzzFun]

happyheart:

Hi, one more please. I am always confused when there is transfer back and forth.Thanks.


Jack and Aqil had some game cards. If Jack gave Aqil 52 cards, he would have the same number of cards as Aqil. If Aqil gave Jack 34 cards, the ratio of the number of cards Aqil had to the number of cards Jack had would be 3:7.How many cards did Jack have at first?

If Jack gave Aqil 52 cards, he would have the same number of cards as Aqil
--> Jack has 52 x 2 = 104 more cards than Aqil at first.

If Aqil gave Jack 34 cards,
--> Jack would have 104 + 34 x 2 = 172 more cards than Aqil

So, 4u --> 172, 1u --> 43
Number of cards Jack has at first = 7 x 43 - 34 = 267

cheers.

[MathIzzzFun]

happyheart:

Hi,

pls help with this question. Thanks!

Andy, Brad, Colin shared money to buya present for their teacher. The ratio of the amount of money contributed by Andy to the total amount contributed by Brad, Colin and Dominic was 1:5. Brad contributed 1/11as much as the total contributed by Dominic. If Andy contributed $2.10 more than Brad, how much did Dominic contribute?

...seems that some info was left out ??

cheers.

[Jwoofamily]

Use model.


If jack give aqil 52 cards and they have same number means the model is like this.

J [ ][ 52 ][ 52 ]
A [ ]

If A gives 34 to J, the model will be as shown below whereby 34+34+52+52=4 units.

J [][][][34][34][ 52 ][ 52 ]
A [][][]

Find 1 unit and you can find solve the problem by tracing back to the original quantity.

[tianzhu]

happyheart:

Hi,

pls help with this question. Thanks!

Andy, Brad, Colin shared money to buya present for their teacher. The ratio of the amount of money contributed by Andy to the total amount contributed by Brad, Colin and Dominic was 1:5. Brad contributed 1/11as much as the total contributed by Dominic. If Andy contributed $2.10 more than Brad, how much did Dominic contribute?

Hi

One possible solution.

A:(: (B+C+D) ------- 1:5 -------3:15

B:D ------1:11

Hence , C ------3

2u ------ 2.1

1u ------ 1.05

D ------- 11*1.05 ------ 11.55

Best wishes

[Michaelia0816]

Tianzhu, can u help me with my sec 1 question, I will send u by PM, note: give me workings

Ty

[tianzhu]

Michaelia0816:

Tianzhu, can u help me with my sec 1 question, I will send u by PM, note: give me workings

Ty

Hi girl

I regret to say that I may not be able to be of any help.

I know next to nothing about the secondary maths as my kid is very much on his own. I’ve not been reading maths books for a few years already.

You may post your questions in the thread on “Secondary maths”.

I am sorry.

Happy New Year

Best wishes

[Michaelia0816]

tianzhu:

Michaelia0816:

Tianzhu, can u help me with my sec 1 question, I will send u by PM, note: give me workings

Ty

Hi girl

I regret to say that I may not be able to be of any help.

I know next to nothing about the secondary maths as my kid is very much on his own. I’ve not been reading maths books for a few years already.

You may post your questions in the thread on “Secondary maths”.

I am sorry.

Happy New Year

Best wishes

Never mind, Ty, happy Chinese New Year

[ozora]

speedmaths.com:

ozora:

I need some pointers in this question.

Zara had 70 more dresses than shirts. She sold 3/4 of the dresses and 3/5 of the shirts. She sold 126 more dresses than shirts. How many dresses were there in beginning?
Besides using models or algebra, any other alternative method like using units to get the answer 460.If possible can provide the solution

Hi ozora,

One Possible Solution:

Look at the 2 denominators; 4 and 5.
A common multiple of 4 and 5 is 20.

Let Zara have 20 boxes of shirts.
Let Zara have (20 boxes + 70) dresses.

She sold 3/4 of the dresses;
She sold (15 boxes + 52.5) dresses.

She sold 3/5 of the shirts;
She sold 12 boxes of shirts.

She sold 126 more dresses than shirts.

15 boxes + 52.5 → 12 boxes + 126
(Subtract 52.5 from both sides of the equation)
15 boxes + 0 → 12 boxes + 73.5
(Subtract 12 boxes from both sides of the equation)
3 boxes + 0 → 0 box + 73.5
3 boxes → 73.5
1 box → 24.5
20 boxes → 490
490 + 70 → 560 dresses (at first)

Hope this helps.

Cheers


speedmaths.com


.

Thanks.