Tutor MathsGuru: Ask me for your burning Maths questions!

[Almighty]

firebird:

Dear Almighty


Thank you very much for your answer.

With best regards
firebird

u'r welcome firebird...

[Almighty]

Almighty:

Hi Dharma,


Question 11 also please.... AM i right for a)?? HOw 2 do (b) section.Stuck while finding the Diameter...



http://www.postimage.org/image.php?v=aVl5jjA

Thankyou very much for Qt:11 Dharma.Am i right in Qt:12?.
Are u able to view my circle problem now? Y no reply to these??? :?

[itro]

Hi,


I have a question on understanding "between" when it is used in Math questions. Sometimes, "between An and B" does not include A and B, but sometimes it does. When we say a number between 10 an 20, the number should not be 10 nor 20. Could you please advise whether I should include 12 noon and 11 o’clock at night when solving the following problem and why?

The grandfather’s clock chimes once when it is 1 o’clock, chimes twice when it is 2 o’clock, chimes thrice when it is 3 o’clock and so forth. How many times will it chime between 12 noon and 11 o’clock at night?

[CoffeeCat]

itro:

Hi,


I have a question on understanding \"between\" when it is used in Math questions. Sometimes, \"between An and B\" does not include A and B, but sometimes it does. When we say a number between 10 an 20, the number should not be 10 nor 20. Could you please advise whether I should include 12 noon and 11 o'clock at night when solving the following problem and why?

The grandfather's clock chimes once when it is 1 o'clock, chimes twice when it is 2 o'clock, chimes thrice when it is 3 o'clock and so forth. How many times will it chime between 12 noon and 11 o'clock at night?

Hmm this is an interesting but rare question so i will present my opinion. It will be cool if you can get back to us when you got the answer.
Ok yes usually between means not including A and B but notice that what is commonly dealt with are termed \"discrete\" or countable quantity.
Time on the other hand is what we called a continuous quantity.
Measurements like Mass, Weight all belong to continuous quantity.
When the clock chimes 12 times at 12 noon, it must take a few seconds to chime 12 times, so it doesn't make sense for us to define the time between 12noon and 11 o clock as starting only after the clock finishes its chimes.
So my guess is 12noon is included, probably because it is what we called a continuous quantity.
May i know where you get this question from?

[Dharma]

Almighty:

Dharma:

[quote=\"Almighty\"]Hi Dharma / MAthguru,


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

1) Is my answer for Qt:12 right? I need a clarification on one thing in this problem.
The shaded length of the first square is 6 cm, how can the whole length of the second square also be 6 cm? (Marked in pencil)
2)Circle question.Unable to get a hint 2 do this.Any help?

Q12 - there is an error w/ the qn. B is NOT a square.

Circle Qn

angle EOD = 180 deg /4 = 45 deg

angle AED = (180deg - 45deg) / 2 = 67.5 deg




http://www.postimage.org/image.php?v=aVl3uA0

[/quote]

[Almighty]

Thankyou every much Dharma…

Have a Good weekend!!!

[itro]

Thanks for your kind reply. The question I quoted is from book \"Math Olympiad for beginner\" by Terry Chew, P25.


Your explanation sounds ok for me and it is probably the only reasonable explanation, but it may not be easy for a P3 pupil to understand.

Sometimes the usage is confusing. For example, \"between you and me\" definitely includes both you and me. But in Math, it does not include.

CoffeeCat:

Hmm this is an interesting but rare question so i will present my opinion. It will be cool if you can get back to us when you got the answer.
Ok yes usually between means not including A and B but notice that what is commonly dealt with are termed \"discrete\" or countable quantity.
Time on the other hand is what we called a continuous quantity.
Measurements like Mass, Weight all belong to continuous quantity.
When the clock chimes 12 times at 12 noon, it must take a few seconds to chime 12 times, so it doesn't make sense for us to define the time between 12noon and 11 o clock as starting only after the clock finishes its chimes.
So my guess is 12noon is included, probably because it is what we called a continuous quantity.
May i know where you get this question from?

[Almighty]

singmathstutor:

Herbie:

I have one qn.


Can someone help me?

The no. shld be placed in a pyramid form.

TX

Row 1 2
Row 2 4 6 8
Row 3 10 12 14 16 18
Row 4 20 22 24 26 28 30 32

What is the largest no on Row 10?

288 is the largetst no. in a certain row. Which row is it?

One more method for your perusal: :idea:

\t1 X 2 = 2\t(1+1)x1
\t\t
\t2 X 4 = 8 \t( 2+2) X 2
\t\t
\t3 X 6 = 18 (3+3) X 3
\t\t
\tSo, ? =\t( 10+ 10) X10
a)\tAns = 200\t
\t\t
b) \t(12 + 12 ) X 12 = 288

[Dharma]

Almighty:

singmathstutor:

[quote=\"Herbie\"]I have one qn.


Can someone help me?

The no. shld be placed in a pyramid form.

TX

Row 1 2
Row 2 4 6 8
Row 3 10 12 14 16 18
Row 4 20 22 24 26 28 30 32

What is the largest no on Row 10?

288 is the largetst no. in a certain row. Which row is it?

One more method for your perusal: :idea:

\t1 X 2 = 2\t(1+1)x1
\t\t
\t2 X 4 = 8 \t( 2+2) X 2
\t\t
\t3 X 6 = 18 (3+3) X 3
\t\t
\tSo, ? =\t( 10+ 10) X10
a)\tAns = 200\t
\t\t
b) \t(12 + 12 ) X 12 = 288

[/quote]Welldone!

[Almighty]

Dharma:

Almighty:

Hi Dharma,


Question 11 also please.... AM i right for a)?? HOw 2 do (b) section.Stuck while finding the Diameter...



http://www.postimage.org/image.php?v=aVl5jjA

Part (a) is correct

Part (b)

Circumference of semi circle = 22cm ... Correct
2 sides of the square : 14cm x 2 = 28cm

Lastly, we need to find out the length of sides of the right angle triangle within the square.Let's call the side of the right angle triangle, \"a\"

We have 4 such right angle triangles in the square of sides 14cm. The right angle triangle has 2 sides of length a and the longer length is 14cm.

If we take 2 of the triangles and rearrange them to form a smaller square of side \"a\". Do the same for the other 2 triangles. We have 2 smaller squares of sides \"a\" and the total area of these 2 squares is the same as
the area if the larger square (196cm2)

2 x a x a =198 196 ? (Typo error ? )
a x a = 99 98
a = 9.95cm (calculator)then, 9.89.... (how to write this?round off 2 decimal point?)

Perimeter
= 22cm + 28cm + 9.95cm
= 59.95cm

Hi Dharma,
I did not understand the above thing in red...pl.clarify if my method below is wrong..
By the way, I have a different answer as given below. Please let me know whether i am right or wrong...


http://www.postimage.org/image.php?v=Ts5weFr