Tutor MathsGuru: Ask me for your burning Maths questions!

[Dharma]

fudgemum:

1)\tThe lengths of two rectangles are 11m and 19m respectively. Their total area is 321meter square. What is the difference in their areas?

There are 2 unknowns with 1 equation…. Need to solve by trial and error.
11 x W1 + 19 x W2 = 321
11W1 + 19W2 = 321

W1 = 5 & W2 = 14 (trial & error)

Difference in area = (19x14) – (11x5) = 211m2

Thanks fudgemum. Strange that a qn can be set with more than 1 answer.

[fudgemum]

Hi,


I am not able to draw the picture.There are three identical circles A, B and C. The circumference of each circle passes through the centre of the other two circles. So we have regions like
A only, B only, C only,
A and B only, B and C only, A and C only,
A and B and C (center portion).

How do you proove that
A and B only, B and C only, A and C only (i.e A insersection B, B intersection C , and C intersection A)
this area is half of the circle.
TIA

[Dharma]

fudgemum:

Hi,


I am not able to draw the picture.There are three identical circles A, B and C. The circumference of each circle passes through the centre of the other two circles. So we have regions like
A only, B only, C only,
A and B only, B and C only, A and C only,
A and B and C (center portion).

How do you proove that
A and B only, B and C only, A and C only (i.e A insersection B, B intersection C , and C intersection A)
this area is half of the circle.
TIA

Hi fudgemum,

Hope this what u r asking.


http://www.postimage.org/image.php?v=Pqn_P8A

[rubydoll]

Kindly refer to the 4 questions posted by me on 17/2/2010.


1) The answer given to question number 4 is 90 people. Therefore, the working and the answer is correct.

2) All the four questions are from Rulang Primary School, Primary 6 CA assessment Paper 2 for 2009.

3) Many many thanks for the help

With best regards
Ruby Doll

[tianzhu]

2)Mrs Tan had $800 at first. 80% of her money consisted of $5 notes and the rest were $10 notes. After she spend some $5 notes, the remaining $5 notes was 60% of the money she had left. How much did Mrs Tan spend? How much did Mrs Tan spend?


Hi Dharma

This question is from Rulang CA1 2009.
http://www.orlesson.org/orp/09Ma/2009-P6-Math-CA1-Rulang.pdf

The answer hinges on the interpretation of this sentence.

After she spent some $5 notes, the remaining $5 notes was 60% of the money she had left.

Does it refer to the physical number of notes or its value?

Best wishes

[ooptimizer]

She spent $400.

[Dharma]

tianzhu:

2)Mrs Tan had $800 at first. 80% of her money consisted of $5 notes and the rest were $10 notes. After she spend some $5 notes, the remaining $5 notes was 60% of the money she had left. How much did Mrs Tan spend? How much did Mrs Tan spend?


Hi Dharma

This question is from Rulang CA1 2009.
http://www.orlesson.org/orp/09Ma/2009-P6-Math-CA1-Rulang.pdf

The answer hinges on the interpretation of this sentence.

After she spent some $5 notes, the remaining $5 notes was 60% of the money she had left.

Does it refers to the physical number of notes or its value?

Best wishes

Hi Tianzhu,
I see it as ….the remaining $5 notes (refers to value of $5 notes) because of the following phrase….was 60% of the money she had left.

[tianzhu]

Hi

Hope this helps.

http://farm3.static.flickr.com/2755/4368482573_272e22a4bb_o.jpg\">

Best wishes

[Dharma]

tianzhu:

Hi

Hope this helps.

http://farm3.static.flickr.com/2755/4368482573_272e22a4bb_o.jpg\">

Best wishes

Brilliant!!!

[fudgemum]

Dharma:

fudgemum:

Hi,


I am not able to draw the picture.There are three identical circles A, B and C. The circumference of each circle passes through the centre of the other two circles. So we have regions like
A only, B only, C only,
A and B only, B and C only, A and C only,
A and B and C (center portion).

How do you proove that
A and B only, B and C only, A and C only (i.e A insersection B, B intersection C , and C intersection A)
this area is half of the circle.
TIA

Hi fudgemum,

Hope this what u r asking.


http://www.postimage.org/image.php?v=Pqn_P8A

Hi Dharma,

Yes. This is what I was asking for. The diagram is correct. I cannot read the solution clearly. But how a P6 child can do in this method?. I think this is SMOPS question.

Thanks.