Q&A - PSLE Math

[MathIzzFun]

Jcong:

The number of the marbles in Box A, Box B and Box C was 195. John added 60 marbles to those in Box A, doubled the number of marbles in Box B and halved the number of marbles in Box C. The ratio of the number of marbles become 4:1:2. What is the total number of marbles in the three boxes now?

Hi

In the end, the ratio of marbles in box A, B, C -
A : B : C
= 4 : 1 : 2
= 8u : 2u : 4u >> total 14u

Initially,
A : B : C
= 8u - 60 : u : 8u

So, 8u - 60 + u + 8u = 195
17u = 255
1u = 15

14u = 14 x 15 = 210

There are 210 marbles in all the boxes now.


cheers.

[BeContented]

Hi,

Need some help to solve this question. I believe I have the solution, just dunno how to use the model method to show/explain to DS. Is there a need to use model actually? Thanks & happy holiday

Question:
The ratio of the number of red counters to the number of blue counters in a box is 7 : 3. If 36 red counters are removed and 24 blue counters added, there will be an equal number of red counters and blue counters. How many red counters are there in the box?

[MathIzzFun]

cwc:

Hi,

Need some help to solve this question. I believe I have the solution, just dunno how to use the model method to show/explain to DS. Is there a need to use model actually? Thanks & happy holiday

Question:
The ratio of the number of red counters to the number of blue counters in a box is 7 : 3. If 36 red counters are removed and 24 blue counters added, there will be an equal number of red counters and blue counters. How many red counters are there in the box?

Hi

Hope this helps :lol:

http://www.flickr.com/photos/62167097@N02/5674641247/in/photostream

cheers.

[BeContented]

MathIzzFun:

cwc:

Hi,

Need some help to solve this question. I believe I have the solution, just dunno how to use the model method to show/explain to DS. Is there a need to use model actually? Thanks & happy holiday

Question:
The ratio of the number of red counters to the number of blue counters in a box is 7 : 3. If 36 red counters are removed and 24 blue counters added, there will be an equal number of red counters and blue counters. How many red counters are there in the box?

Hi
Hope this helps :lol:

http://www.flickr.com/photos/62167097@N02/5674641247/in/photostream

cheers.

Hi,
Thanks for the help. So I see, I need to draw the model before and after, thanks.

One more question, How many red counters are there in the box? Should I be looking at the red counters before 36 was removed or after it's being removed. I found this a little vague.

[MathIzzFun]

cwc:

MathIzzFun:

[quote=\"cwc\"]Hi,

Need some help to solve this question. I believe I have the solution, just dunno how to use the model method to show/explain to DS. Is there a need to use model actually? Thanks & happy holiday

Question:
The ratio of the number of red counters to the number of blue counters in a box is 7 : 3. If 36 red counters are removed and 24 blue counters added, there will be an equal number of red counters and blue counters. How many red counters are there in the box?

Hi
Hope this helps :lol:

http://www.flickr.com/photos/62167097@N02/5674641247/in/photostream

cheers.

Hi,
Thanks for the help. So I see, I need to draw the model before and after, thanks.

One more question, How many red counters are there in the box? Should I be looking at the red counters before 36 was removed or after it's being removed. I found this a little vague.[/quote]Hi

You are welcome

This is an \"if\" question ie the counters are not changed at all. So, the answer is for the number of counters in the box \"initially\" ie if the counters were not changed.

cheers.

[BeContented]

MathIzzFun:

Hi

You are welcome

This is an \"if\" question ie the counters are not changed at all. So, the answer is for the number of counters in the box \"initially\" ie if the counters were not changed.

cheers.

Oh yah Talk about telling my son to read carefully Thanks again.

[chrisu]

Another P6 question and I wonder if the question is correct;


Mr. Wong had 207 apples and oranges. After he had sold 50% of the apples and 40% of the oranges, he had 45 more oranges than apples left. How many fruits did he have left?

Thank you.

[shurley197323]

Pls help. John had 993 tables and chairs at first.

After he sold 2/5 of the tables and 5/8 of the chairs, he had 459 tables and chairs left.
How many tables did he sell?

[tianzhu]

chrisu:

Another P6 question and I wonder if the question is correct;

Mr. Wong had 207 apples and oranges. After he had sold 50% of the apples and 40% of the oranges, he had 45 more oranges than apples left. How many fruits did he have left?
Thank you.

Hi

I guess you just want to confirm the answers.

I did a quick check, and the answers are 81 oranges and 36 apples giving a total of 117 fruits.

Best wishes

[greenfinger]

a)Each of the three cards is printed with a different whole number.The smallest number is 25.Two cards are drawn at a time and the numbers on the cards are added together.The sums are 56,68 and 74


What is the largest number on the cards? :?


PLs anyone guide me ,thank you