Q&A - PSLE Math

[Andrew Lee]

tianzhu:

Andrew Lee:

Hello, can help me solve this headpain sch question ?

http://i53.tinypic.com/2s6sjmp.jpg\">

Hi

Just to confirm, is it 'Total area of X and Y is equal to 3/4 of Z\" or \"Total area of X and Z is equal to 3/4 of Y\"

Best wishes

Hi, is \"Total area of X and Y is equal to 3/4 of Z\" . Is it wrong \"...of Z\" ?

[SBC dad]

If this question been posted before, sorry for posting here again. But could someone help to confirm the answer as there is no solution given but only suggested answer is 0954h. Question from CHIJ 2011 Prelims.


Ans : A rectangular tank measuring 40cm by 30cm by 40cm was 1/6 filled with water. At 0930h, Tap X waith water flowing out at a rate of 3 litre per minute was turned on.
At 0932h, Tap Y was turned on to drain water out of the tank at a fixed rate.
At 0943h, the tank was 75% filled with water.
At what time would the tank be filled to the brim ?

MTIA.

[Vanilla Cake]

SBC dad:

Ans : A rectangular tank measuring 40cm by 30cm by 40cm was 1/6 filled with water. At 0930h, Tap X waith water flowing out at a rate of 3 litre per minute was turned on.At 0932h, Tap Y was turned on to drain water out of the tank at a fixed rate.At 0943h, the tank was 75% filled with water.At what time would the tank be filled to the brim ?

Hi SBC dad,
Your question had been answered by http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&p=583076 on page 422. Correct answer is 0949 h and not 0954 h.

[SBC dad]

Vanilla Cake:

SBC dad:

Ans : A rectangular tank measuring 40cm by 30cm by 40cm was 1/6 filled with water. At 0930h, Tap X waith water flowing out at a rate of 3 litre per minute was turned on.At 0932h, Tap Y was turned on to drain water out of the tank at a fixed rate.At 0943h, the tank was 75% filled with water.At what time would the tank be filled to the brim ?

Hi SBC dad,
Your question had been answered by http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&p=583076 on page 422. Correct answer is 0949 h and not 0954 h.

Great ! My son got it correct ! Thanks Vanilla for answering my answer

[MathIzzzFun]

Andrew Lee:

WWong:

Hi tianzhu,


Thank you very much for your kind guidance.

WWong

Hello, can help me solve this headpain sch question ?
http://i53.tinypic.com/2s6sjmp.jpg\">

Hi

You can use MD as done for a similar question - http://www.flickr.com/photos/62167097@N02/5679183503/in/photostream

or we can also use \"units\" & \"parts\" ie simultaneous equations/algebra...

**note that Y and Z in the diagram should be swapped**

X = 6 units
Y = 9 parts
Shaded = 1/2 X + 1/3 Y = 3 units + 3 parts

X+Y = 3/4 C, C = 4/3 (X+Y) = 8 units + 12 parts ...(eq 1)

3/10 C is shaded, so 3 units + 3 parts = 3/10 C
C = 10 units + 10 parts = 8 units + 12 parts (from eq 1)
so 1 unit = 1 part

X : Y = 6 units : 9 parts = 6 units : 9 units = 2 : 3

cheers.

[MathIzzzFun]

Andrew Lee:

WWong:

Hi tianzhu,


Thank you very much for your kind guidance.

WWong

Morning,
Janelle went to a florist to buy some flowers. She spent 1/6 of her money on q bouquet of roses and $154 on a bouquet of lilies. She spent 1/9 of her remaining amount on a bouquet of carnation flowers. If the amount of money left was $240 more than 1/4 of the amount she had at first, how much had she left? :?

Hi

http://i56.tinypic.com/i69p3n.jpg\">

cheers.

[Muku]

MathIzzzFun:

Andrew Lee:

[quote=\"WWong\"]Hi tianzhu,


Thank you very much for your kind guidance.

WWong

Hello, can help me solve this headpain sch question ?
http://i53.tinypic.com/2s6sjmp.jpg\">

Hi

You can use MD as done for a similar question - http://www.flickr.com/photos/62167097@N02/5679183503/in/photostream

or we can also use \"units\" & \"parts\" ie simultaneous equations/algebra...

X = 6 units
Y = 9 parts
Shaded = 1/2 X + 1/3 Y = 3 units + 3 parts

X+Y = 3/4 C, C = 4/3 (X+Y) = 8 units + 12 parts ...(eq 1)

3/10 C is shaded, so 3 units + 3 parts = 3/10 C
C = 10 units + 10 parts = 8 units + 12 parts (from eq 1)
so 1 unit = 1 part

X : Y = 6 units : 9 parts = 6 units : 9 units = 2 : 3

cheers.[/quote]Hi hi,

For your second equation, \"3/10 C is shaded, so 3 units + 3 parts = 3/10 C\", it doesn't look correct to me. Looks more like 3 parts = 3/10C. The 3 units is not part of circle Z.

I can't seem to get a logical answer. Can help reconfirm if there's anything wrong with this sum?

Thanks!

[ozora]

Need help.Jim has 3 cubicle tanks of different sizes. The length of Tank A is twice the length of Tank B and the length of Tank B is twice the length of Tank C. Jim filled 20% of Tank A,35%of Tank B and 40% of Tank C with water at first. He then poured all the water from Tank B and Tank C into Tank A. What percentage of Tank A is filled with water now? Can you please solve this question?

[Andrew Lee]

MathIzzzFun:

Andrew Lee:

[quote=\"WWong\"]Hi tianzhu,


Thank you very much for your kind guidance.

WWong

Hello, can help me solve this headpain sch question ?
http://i53.tinypic.com/2s6sjmp.jpg\">

Hi

You can use MD as done for a similar question - http://www.flickr.com/photos/62167097@N02/5679183503/in/photostream

or we can also use \"units\" & \"parts\" ie simultaneous equations/algebra...

X = 6 units
Y = 9 parts
Shaded = 1/2 X + 1/3 Y = 3 units + 3 parts

X+Y = 3/4 C, C = 4/3 (X+Y) = 8 units + 12 parts ...(eq 1)

3/10 C is shaded, so 3 units + 3 parts = 3/10 C
C = 10 units + 10 parts = 8 units + 12 parts (from eq 1)
so 1 unit = 1 part

X : Y = 6 units : 9 parts = 6 units : 9 units = 2 : 3

cheers.[/quote]Thank you so much :imcool:

[Andrew Lee]

MathIzzzFun:

Andrew Lee:

[quote=\"WWong\"]Hi tianzhu,


Thank you very much for your kind guidance.

WWong

Morning,
Janelle went to a florist to buy some flowers. She spent 1/6 of her money on q bouquet of roses and $154 on a bouquet of lilies. She spent 1/9 of her remaining amount on a bouquet of carnation flowers. If the amount of money left was $240 more than 1/4 of the amount she had at first, how much had she left? :?

Hi

http://i56.tinypic.com/i69p3n.jpg\">

cheers.[/quote]Hello, here got two questions need help
Q1. Mr Singh was travelling at a constant speed from Town A to Town B. he passed a car travelling at a constant speed of 90km/h in the opposite direction. 1hr 30min later,Mr Singh reached Town B but the car still 25km away from Town A. If Mr Singh took 4hrs to complete the whole jorney. What is the distance between the 2 towns?

Q2. At first, Din had only $5 notes and Bella had only $2 notes. The number of notes Bella had is 80% of Din's notes. When Bella gives Din $100.00, the number of notes Din has now is 70% more than Bella. How many notes did Din have at first? :imdrowning: