Q&A - PSLE Math

[YumYum]

MathIzzzFun:

YumYum:

Hi, I need help with these qns:


3) when mr gopal was 40 yrs old, his son, Kumar, was twice the age of his daughter, Rita. Mr gopal would be 3 times his son's age when rita was 12 yrs old. How old would Mr gopal be when Rita was 20 yrs old?

Thanks

similar question here...

http://www.flickr.com/photos/62167097@N02/5679985631/in/photostream

Gopal --> 40
Rita --> 1 unit
Kumar --> 2 units (age difference between Rita and Kumar = 1unit)


Rita --> 12
Kumar --> 12 + 1 unit (age difference remains the same)
Gopal --> 36 + 3 units (age difference between Gopal and Kumar = 24 + 2 units)

so, when Gopal --> 40 = 2 units (Kumar's age) + 24 + 2 units
1 unit --> 4

Age difference between Gopal and Rita = 40 - 4 = 36
Rita --> 20
Gopal --> 56

cheers.

Dear MathIzzzFun, thank you for yr usual and prompt help :rahrah:

[imacsg]

Dear MathIzzzFun,


I also have the same ans, but find a bit odd, in fraction. So I think the question is not set properly.
Thank you for yr usual and prompt help.

[bndreve]

Hi, need help with the following question. Thanks.


Issac had some red and blue marbles in a container. First, he added in 22 red marbles and as a result, 40% of the marbles in the container were blue. Next, he added in another 180 blue marbles and as a result, 60% of the marbles were blue. Finally, he removed some red marbles such that the ratio of the remaining red marbles to the remaining blue marbles was 1:3.
a) How many red mables did he have at first?
b) How many red marbles did he remove?

[tianzhu]

bndreve:

Hi, need help with the following question. Thanks.


Issac had some red and blue marbles in a container. First, he added in 22 red marbles and as a result, 40% of the marbles in the container were blue. Next, he added in another 180 blue marbles and as a result, 60% of the marbles were blue. Finally, he removed some red marbles such that the ratio of the remaining red marbles to the remaining blue marbles was 1:3.
a) How many red mables did he have at first?
b) How many red marbles did he remove?

Hi

I've drawn more MD than necessary, once students understand the concept they may consodilate the steps.

Hope this helps.

Best wishes

http://farm9.staticflickr.com/8046/8416271396_764a03e295_z.jpg\">

[SAHMwith2boys]

Hi, I have a question, it has more to do with the understanding of the question:


1. The original temp. is 70 degree. If the final temp. is 60% lower than the original temp., what is the final temp.?

2. The original temp. is 70 degree. If the final temp. is 60% of the original temp., what is the final temp.?

From my understanding is that the final temp. in (1) should be 28 degree while in (2) should be 42 degree. Is my understanding right?

[tianzhu]

SAHMwith2boys:

Hi, I have a question, it has more to do with the understanding of the question:


1. The original temp. is 70 degree. If the final temp. is 60% lower than the original temp., what is the final temp.?

2. The original temp. is 70 degree. If the final temp. is 60% of the original temp., what is the final temp.?

From my understanding is that the final temp. in (1) should be 28 degree while in (2) should be 42 degree. Is my understanding right?

Hi

You are correct.

Best wishes

[superhappy]

tianzhu:

SAHMwith2boys:

Hi, I have a question, it has more to do with the understanding of the question:


1. The original temp. is 70 degree. If the final temp. is 60% lower than the original temp., what is the final temp.?

2. The original temp. is 70 degree. If the final temp. is 60% of the original temp., what is the final temp.?

From my understanding is that the final temp. in (1) should be 28 degree while in (2) should be 42 degree. Is my understanding right?

Hi

You are correct.

Best wishes

Hi,

I need help on this question,
1. Benedict & Jeremy each has some money. If Benedict spnds $45 per day and Jeremy spends $15 per day, Benedict would have left $120 by the time Jeremy spends all his money. If Benedict spends $15 per day and Jeremy spends $45 per day, Benedict wld have left $1080 by the time Jeremy spends all his money. How much money does each of them have?

Thanks :salute:

[tianzhu]

superhappy:

Hi,

I need help on this question,
1. Benedict & Jeremy each has some money. If Benedict spnds $45 per day and Jeremy spends $15 per day, Benedict would have left $120 by the time Jeremy spends all his money. If Benedict spends $15 per day and Jeremy spends $45 per day, Benedict wld have left $1080 by the time Jeremy spends all his money. How much money does each of them have?

Thanks :salute:

Hi

Good Morning.

Here's a similar type of question, hope this helps.

Best wishes

http://farm6.staticflickr.com/5142/5614468685_555807d62e_z.jpg\">

[Jolyn]

Mandy ate 5/12 of her cookies and gave 3/7 of the remainder to jane. If she had 16 cookies left, how many cookies did Mandy have at first?



Hope you can reply me by today.

[YumYum]

Hi, Can anyone pls help with this Qn:


Calvin had $840 more than Daniel. Calvin gave 75% of his money to Daniel. Daniel gave 5/7 of his money to Calvin. In the end, Calvin had $700 more than Daniel. How much did Calvin have at first?

Thanks!