Q&A - PSLE Math

[small]

Hi,


Please help and many thanks in advance.

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[tianzhu]

Hi moderator


Good Morning.

To aviod confusion, please help to delete post as my answer is incorrect.

Best wishes.

[mathnoobs]

tianzhu:

Hi small


Good Morning.

Where is this question from?

Jan
Spent ----- 3 units (15 units)
Remaining ------ 7 units (35 units)

Feb
Saved ----- 7 units (1/5*35units)

8*3.95 ------ 31.6

3 parts ----- parents’ tour

5 parts remaining

2 parts ------saved ------- 6219.85
3 parts ------ 6219.85*3/2 ------ 9329.75 ( money given to parents)
8 parts ------ 24879.40

7 units ------ 24879.4+31.6
7 units ------ 24911
50 units ------ 177935.71 (money in the bank at first)

Best wishes

Hi Tianzhu
this is a really hard question to understand. Thanks for the solution.
However, I am confused by these sentences:

Then she purchased 8 pens at $3.95 each. When she heard heard her parents were going on a tour, she gave them 3/8 of he amount she had left.

It looks like she spent the money in March. So the total amount of money spent in March is (8x3.95) + 3 parts. However, from your workings, it looks like she only spent 3 parts in March. :? I can't see how that is done.

[tianzhu]

mathnoobs:

Hi Tianzhu
this is a really hard question to understand. Thanks for the solution.
However, I am confused by these sentences:

Hi

Thank you for reading my solution. You’re certainly a very enthusiastic maths mummy.

For these 7 units in Feb, Nicole spent $31.60 on 8 pens and gave 3 parts of the remainder to her parents. After that, she had 5 parts left. She saved 2 parts (40% of 5 parts).

Hence, we’ll have 2 parts which is equal to $6219.85.

Best wishes

[small]

tianzhu:

Hi small


Good Morning.

Where is this question from?

Jan
Spent ----- 3 units (15 units)
Remaining ------ 7 units (35 units)

Feb
Saved ----- 7 units (1/5*35units)

8*3.95 ------ 31.6

3 parts ----- parents’ tour

5 parts remaining

2 parts ------saved ------- 6219.85
3 parts ------ 6219.85*3/2 ------ 9329.75 ( money given to parents)
8 parts ------ 24879.40

7 units ------ 24879.4+31.6
7 units ------ 24911
50 units ------ 177935.71 (money in the bank at first)

Best wishes

Hi Tianzhu,

As usual, once again many thanks for your solution. This question was extraceted from a Maths Heuristic Assessment of my son.

Will need some time to digest the solution. Btw, I am confused by the '7 units of Jan' and '7 units of Feb'. :oops:

[tianzhu]

small:

Btw, I am confused by the '7 units of Jan' and '7 units of Feb'. :oops:

Hi

Changing percentages into units and using equivalent ratios for the month of Jan.

30% ------ 3 units ------- 15 units
70% ------ 7 units ------- 35 units.

In Feb, the amount saved is 1/5*35 units ------ 7 units.

Best wishes

[small]

Hi Tianzhu,


Finally I understood the solution.

I misinterpreted the question as I thought Nicole saved 7 units in Feb, then the balance which is 28 units, she spent $31.60 for 8 pens and gave 3/8 of (28units – 31.60) to her parents in March; 40% of the remainder is $6219.85.


In fact it should be:
Nicole spent 30% and saved 70% in Jan; After spending in Feb, she saved 14% (1/5 of 70%). For this 14%, Nicole spent $31.60 on 8 pens and gave 3 units of the remainder to her parents, she left with 5 units now and saved 2 units (40% of 5 units), and this 2 units equal to $6219.85

a)\t
2U ----- 6219.85
3U ----- 9329.775

b)
2U ----- 6219.85
8U ----- 24879.40

14% ----- 24879.40 + 31.60
14% ----- 24911
100% ----- 177 935.71

[speedmaths.012624com]

small:

This question was extracted from a Maths Heuristic Assessment of my son.

Hi Small,

What was the answer given to your son?

I interpreted the question differently, and got $8500 as her original savings in the bank.

Cheers


Speedmaths.com


.

[small]

speedmaths.com:

small:

This question was extracted from a Maths Heuristic Assessment of my son.

Hi Small,

What was the answer given to your son?

I interpreted the question differently, and got $8500 as her original savings in the bank.

Cheers


Speedmaths.com
.

Hi Speedmaths,

The teacher still have not go thru' with the class, btw I am quite interested in your interpretation on this question, mind to share how did you get $8500 as her original savings in the bank?

TIA..

[mathnoobs]

I'm at a loss on the interpretation here:

Nicole had saved a certain amount of money. In January, she spent 30% of her savings. In February, she managed to save 1/5 of the amount of money she had left. Then she purchased 8 pens at $3.95 each. When she heard heard her parents were going on a tour, she gave them 3/8 of the amount she had left. In March, she managed to save 40% of her savings left. Finally she had $6219.85 in the bank.

In Feb, she managed to save ...Then she purchase 8 pens...

The word \"Then\" came after the statement that she saved 1/5 in Feb. That would indicate that she purchased the 8 pens after Feb, therefore in the month of March. She also gave 3/8 to her parents.
The parent statement came directly after the pen statement, so this would indicate that both are on the same time frame, ie. March.