Tutor MathsGuru: Ask me for your burning Maths questions!

[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

[Dharma]

Almighty:

Dharma:

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

The correct way to calculate the perimeter of the shaded area is to use the original diagram.

You have done it correctly by calculating the arc lengths of the quadrant instead of the chord of the quadrant.

I was carried away with the transformed diagram in part (a). My apologies.

[Almighty]

Thanks Dharma!!!

[Almighty]

Hi all,


This is a problem already posted earlier in this forum n solved.
But i hv a doubt in this solution.

The problem :

During a sale, the price of a skirt was reduced from $256.80 to
$214 inclusive of GST of 7%. What was the decrease in price of the skirt, excluding GST?

Forum answer: (Dont remember who answered...Pl.forgive)

Skirt before GST before discount = 256.80*0.93= 238.82\t\t\t\t\t\t\t
Skirt before GST after discount = 214*0.93 = 199.02\t\t\t\t\t\t\t

Decrease in skirt before GST = $39.80 (Ans in 2 significant figure, then $40)

In one step will be, discount excluding GST = (256.8-214)*0.93 = $39.80

My solution:
Before discount and GST:\t\t
107% ---- 256.80 \t\t
100% ---- ? (240)\t\t
\t\t
After Discount and GST\t\t
107% ----214\t\t
100% -------? ($40)\t\t
(OR ) ONE STEP SOLUTION:\t\t
\t\t
107% --- 42.80 ( 256.80 - 214)\t\t
100% --- ?\t\t
\t\t
Ans = $40\t\t

Can anyone clarify which is correct? If i'm wrong please let me know why i should not assume in my way.. :?

[MOE Hater]

Almighty:

Hi all,


This is a problem already posted earlier in this forum n solved.
But i hv a doubt in this solution.

The problem :

During a sale, the price of a skirt was reduced from $256.80 to
$214 inclusive of GST of 7%. What was the decrease in price of the skirt, excluding GST?

Forum answer: (Dont remember who answered...Pl.forgive)

Skirt before GST before discount = 256.80*0.93= 238.82\t\t\t\t\t\t\t
Skirt before GST after discount = 214*0.93 = 199.02\t\t\t\t\t\t\t

Decrease in skirt before GST = $39.80 (Ans in 2 significant figure, then $40)

In one step will be, discount excluding GST = (256.8-214)*0.93 = $39.80

My solution:
Before discount and GST:\t\t
107% ---- 256.80 \t\t
100% ---- ? (240)\t\t
\t\t
After Discount and GST\t\t
107% ----214\t\t
100% -------? ($40)\t\t
(OR ) ONE STEP SOLUTION:\t\t
\t\t
107% --- 42.80 ( 256.80 - 214)\t\t
100% --- ?\t\t
\t\t
Ans = $40\t\t

Can anyone clarify which is correct? If i'm wrong please let me know why i should not assume in my way.. :?

Your method is the way I would go about it. Anyother forummers care to share their views?

[mathsguru]

super star:

Hi Mathsguru

thanks for ur help.I have another problem pls help to solve this
Aurdrey & belle have some money each.If audrey spends $18 &belle spends $24 each day,audrey will still have $25 left when belle has spent all her money.If audrey spends $13 &bellespends $30each day,audrey will have $139 left when belle has spent all her money.How much money do they have altoghter?

Hi Superstar,

Here's my solution. Very sorry for the delay!


MathsGuru

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