Tutor MathsGuru: Ask me for your burning Maths questions!

[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.

[Dharma]

fudgemum:

Dharma:

[quote=\"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.[/quote]Hope it is better now.

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


http://www.postimage.org/image.php?v=aVboQ1i

[trytry]

Dharma:

fudgemum:

[quote=\"Dharma\"]
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.

Hope it is better now.

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


http://www.postimage.org/image.php?v=aVboQ1i[/quote]

For a P6 this problem is solved by shifting parts. I do not have the tools to
show


Just draw 4 equilateral triangles with one at the center to form a big equilateral triangle. Extend Line RS to the circumference of cirlce C to form a half cirle. Draw a arc similar to PR but opposite way. Shift parts into half circle PRX ( X will be a point when u extend RS to the circumference. parts to shift willbe intersection of A &B and B&C. A&C already in the half circle.

Hope this help.

[happies]

Hi


Thanks for helping to solve below questions.

1) The ratio of John’s age to his uncle’s age is 1:4. In 30 years’ time, the ratio will become 2:3. How old is John now?

2) The salary of Mr Lim and Mr Tan was in the ratio 3:5. After they gave away an equal amount of $3500 to their wives, the ratio became 1:4. What was Mr Lim’s salary?

[tianzhu]

Hi

Hope this helps.
http://farm5.static.flickr.com/4002/4375904850_1a606a0e6e_o.jpg\">


As for Q2, the salary difference remains the same.You may want to try it out first.

Best wishes