Tutor MathsGuru: Ask me for your burning Maths questions!

[Dharma]

Q19


When Betty and David at Pt C, they walked 1/2 the circumference in total. When they meet for the 2nd at Pt D, they walked the circumference in total ( from Pt C to Pt D)

AC = 80m
BD = 60m

2 x AC = CB + BD
CB = 160m - 60m = 100m

Circumference = (60m + 100m) x 2 = 360m

[clblinym]

Dharma:

Q19


When Betty and David at Pt C, they walked 1/2 the circumference in total. When they meet for the 2nd at Pt D, they walked the circumference in total ( from Pt C to Pt D)

AC = 80m
BD = 60m

2 x AC = CB + BD
CB = 160m - 60m = 100m

Circumference = (60m + 100m) x 2 = 360m

It is very nice of you, Dharma. Really appreciate your great help.
Merry Christmas.

[clblinym]

Dharma:

Q19


When Betty and David at Pt C, they walked 1/2 the circumference in total. When they meet for the 2nd at Pt D, they walked the circumference in total ( from Pt C to Pt D)

AC = 80m
BD = 60m

2 x AC = CB + BD
CB = 160m - 60m = 100m

Circumference = (60m + 100m) x 2 = 360m

Dear Dhrma,
I still can't figure out how you get
2 x AC = CB + BD. Can you explain? Thanks

Thanks,
Amy

[john69888]

Dear All,


How to print the JPG file math guru posted on Kiasuparents? I download the jpg files and print the files, but it is NOT clear.

Pls kindly tell how to print the JPG file math guru posted on Kiasuparents.

Thanks,

Liew

mathsguru:

suiyuan:

1)During a warehouse book sale, Sally spent 62.5% of her money on 24 books and 18 pens. She also spent 25% of her remaining money on 18 files. Each pen costs 8/9 as much as the price of one book. The file costs $7.80 less than a book. Find the total cost of one book and one pen.

Hi Suiyuan,

Please see my solution and explanation in the attached picture.

http://www.postimage.org/image.php?v=aV1esa5S

Cheers,
MathsGuru

[Dharma]

clblinym:

Dharma:

Q19


When Betty and David at Pt C, they walked 1/2 the circumference in total. When they meet for the 2nd at Pt D, they walked the circumference in total ( from Pt C to Pt D)

AC = 80m
BD = 60m

2 x AC = CB + BD
CB = 160m - 60m = 100m

Circumference = (60m + 100m) x 2 = 360m

Dear Dhrma,
I still can't figure out how you get
2 x AC = CB + BD. Can you explain? Thanks

Thanks,
Amy

Hi Amy,

Both Betty and David walk at constant speed.
When they meet at Point C, notice that in total both of them covered a distance of 1/2 the circumference of the circle.

Then from Point C to Point, in total both them covered a distance that is equal to the circumference of the circle.

Distance covered by Betty from Point A to Point C when she first met David = AC.

Distance covered by Betty from Point C to Point D when she met David again = CB + BD

Since her walking speed is constant, she had to walk twice the distance from C to D as compared to the distance she walked from A to C.

So,

CB + BD = 2 X AC

[Dharma]

clblinym:

Hi, Can anyone help in solving the following 4 questions.


They are from SMOPS 2004. Thanks in advance!!
http://postimage.org/image/11liujpr8/

Thank you very much.


Regards,
Amy

http://postimage.org/image/2t4uonlj8/

[clblinym]

Dharma:

clblinym:

[quote=\"Dharma\"]Q19


When Betty and David at Pt C, they walked 1/2 the circumference in total. When they meet for the 2nd at Pt D, they walked the circumference in total ( from Pt C to Pt D)

AC = 80m
BD = 60m

2 x AC = CB + BD
CB = 160m - 60m = 100m

Circumference = (60m + 100m) x 2 = 360m

Dear Dhrma,
I still can't figure out how you get
2 x AC = CB + BD. Can you explain? Thanks

Thanks,
Amy

Hi Amy,

Both Betty and David walk at constant speed.
When they meet at Point C, notice that in total both of them covered a distance of 1/2 the circumference of the circle.

Then from Point C to Point, in total both them covered a distance that is equal to the circumference of the circle.

Distance covered by Betty from Point A to Point C when she first met David = AC.

Distance covered by Betty from Point C to Point D when she met David again = CB + BD

Since her walking speed is constant, she had to walk twice the distance from C to D as compared to the distance she walked from A to C.

So,

CB + BD = 2 X AC[/quote]Hi, Dharma
Now I can figure it out.
I really appreciate your kind sharing and patience !!

Regards,
Amy

[john69888]

Dear All,


How to print the JPG file math guru posted on Kiasuparents? I download the jpg files and print the files, but it is NOT clear.

john69888:

Dear All,

How to print the JPG file math guru posted on Kiasuparents? I download the jpg files and print the files, but it is NOT clear.

Pls kindly tell how to print the JPG file math guru posted on Kiasuparents.

Thanks,

Liew

mathsguru:

[quote=\"suiyuan\"]1)During a warehouse book sale, Sally spent 62.5% of her money on 24 books and 18 pens. She also spent 25% of her remaining money on 18 files. Each pen costs 8/9 as much as the price of one book. The file costs $7.80 less than a book. Find the total cost of one book and one pen.

Hi Suiyuan,

Please see my solution and explanation in the attached picture.

http://www.postimage.org/image.php?v=aV1esa5S

Cheers,
MathsGuru

[/quote]

[clblinym]

Dharma:

clblinym:

Hi, Can anyone help in solving the following 4 questions.


They are from SMOPS 2004. Thanks in advance!!
http://postimage.org/image/11liujpr8/

Thank you very much.


Regards,
Amy

http://postimage.org/image/2t4uonlj8/

Hi, Dharma

Thank you very much. Your explanation is easy to understand. I really appreciate your help.

Regards,
Amy

[Dharma]

clblinym:

Hi, Can anyone help in solving the following 4 questions.


They are from SMOPS 2004. Thanks in advance!!
http://postimage.org/image/11lki3290/

Thank you very much.


The answers are
Q19 (360 m)
Q28 (24 cm2)
Q29 (64665912)
Q30 (8, 11, 81) (12,4,84) (4, 18, 78 )


Regards,
Amy

Assume that telephone number is ABCDEFGH
ABC + DEFGH = 66558
ABCDE + FGH = 65577
A = 6
D = 6

60000 + 1000E + 100(6 + F) + 10(B + G) + (C + H) = 66,558
60000 + 1000B + 100(C + F) + 10(6 + G) + (E + H) = 65,577

E is either 6 or 5
B is either 5 or 4
C + H => 8 or 18
E + H => 7 or 17

6 + G = 7. So, G = 1
We know that
C + H = 8 and
E + H = 7

B + G = 5
B = 4
C + F = 15
6 + F = 15
C = 6
F = 9
1+ E = 6
E = 5
C + H = 8
H = 8 – 6 = 2
Tel number = ABCDEFGH = 64665912