Tutor MathsGuru: Ask me for your burning Maths questions!

[Tnsp]

optimistforum:

Please help on the answer to the question below.



John and Tom race around a circular track, divided like the face of a clock, into 12 sections. If John gives Tom four sections start and runs half as fast again as Tom, at what point on the track will he overtake Tom? (Assume on the clock face that John and Tom start at 12 and 4, respectively).

The answer is 12, however, if John gives Tom four sections starts and is half as fast, surely does not half as fast mean that John is running at half the speed of Tom. And if he is 4 sections behind, surely Tom will win. Unless half as fast means that John runs at 1.5 times of Tom. Tearing my hair out here. Please help!!!

Edit. QUESTION to MOD. Can this post be migrated to the sticky \"ask the maths tutor a burning question\"

Tom: 4 / 5 / 6 / 7 / 8 / 9 / 10 ...
John: 12/ 2 / 4 / 6 / 8 / 10 (over-taken Tom)

How come is 12 ?

I think there must a error in the question. John let Tom go in front, and run \"slower\" common sense tells me that John will never overtake Tom.
It should be twice as fast.

If this question is to be a 'trick' question, i.e., John 'overtakes' Tom after one round being behind...but WAH !

[CJM]

hi all,


need your expertise on this…

Susan wants to buy 7 dolls which are selling at the same price. However, she needs another $11.40 in order to buy them.
She then decides to buy 3 dolls instead and and $20.20 left after that. What is the cost of each doll ?

cheers…

[firebird]

Dear Maths Guru


Good afternoon.

Please help me on the following P6 maths:

An equal number of girls and boys went to a party. The ratio of the number of girls who wore spectacles to the number of boys who wore spectacles was 11 : 3. The ratio of the number of boys who did not wear spectacles was 3 : 5.

a) Find the ratio of the number of boys who wore spectacles to the number of boys who did not wear spectacles.

b) There were 7 times as many girls as boys who left the party. The ratio of the number of girls to the number of boys who remained at the party became 35 : 38. If there were 560 girls remaining at the party, how many girls left the party?

Thank you
Firebird

[Muffins]

elkniwt:

Muffins:

[quote=\"Skydust\"]Hello, How do you do this question?


Denise, Ginny and Florence each made some bookmarks for sale. At first, Denise had 1365 bookmarks more than Ginny. Then Denise sold 420 bookmarks and made another 175 bookmarks. Florence sold 140 bookmarks and made another 350 bookmarks. Ginny made some more bookmarks and her number of bookmarks doubled. In the end, all three girls had the same number of bookmarks. Find the total number of bookmarks the three girls had at first.

Please correct me if I'm wrong Dharma and/or Tianzhu, or anyone who basically spots a mistake in this working.

1365 - 420 + 175 = 1120 => Number of bookmarks extra Denise has in regard to Ginny

If D had 1390 more bookmarks than G and G's doubled unit equals it, then it is safe to assume that 1 unit is 1120.

So for D, she had 2 units + 245, so 1120 X 2 + 245 = 2485
G - 1120 (1 unit)
F - 1120 - 210 = 910

Hi Muffins,

I got the same ans for D & G.
For F, since she finally ends up with the same number as G, I took it as 2 units, hence
F = 2 x 1120 - 210 = 2030

Total = 5 x 1120 + 245 - 210 = 5635

Regards.[/quote]Thanks! I didn't spot my error before!!! :thankyou:

[blessedami]

CJM:

hi all,


need your expertise on this...

Susan wants to buy 7 dolls which are selling at the same price. However, she needs another $11.40 in order to buy them.
She then decides to buy 3 dolls instead and and $20.20 left after that. What is the cost of each doll ?

cheers..

My DS got this answer:

7-3=4
$20.20+$11.40=$31.60
$31.60/4= $7.90

Mathsguru/Dharma- please correct him if he is wrong

[blessedami]

firebird:

Dear Maths Guru


Good afternoon.

Please help me on the following P6 maths:

An equal number of girls and boys went to a party. The ratio of the number of girls who wore spectacles to the number of boys who wore spectacles was 11 : 3. The ratio of the number of boys who did not wear spectacles was 3 : 5.
a) Find the ratio of the number of boys who wore spectacles to the number of boys who did not wear spectacles.

b) There were 7 times as many girls as boys who left the party. The ratio of the number of girls to the number of boys who remained at the party became 35 : 38. If there were 560 girls remaining at the party, how many girls left the party?

Thank you
Firebird

Hi Firebird,

My DS thinks there is a typo error in this part of the question. Could you make it clearer?

With the figures given, this is the answer that he has for Part b)

Since there is an equal number of girls and boys in the beginning, the difference at the end would be
7 units-1unit= 6 units

To make the difference 6 units,
35:38 = 70:76

So, at first the ratio is,
77:77

Number of girls who left = 7 units

70units = 560
7 units = 56

Cheers,

[singmathstutor]

blessedami:

CJM:

hi all,


need your expertise on this...

Susan wants to buy 7 dolls which are selling at the same price. However, she needs another $11.40 in order to buy them.
She then decides to buy 3 dolls instead and and $20.20 left after that. What is the cost of each doll ?

cheers..

My DS got this answer:

7-3=4
$20.20+$11.40=$31.60
$31.60/4= $7.90

Mathsguru/Dharma- please correct him if he is wrong

Your son is spot on.

[maths6a]

In the figure, KE = EL, AE = ED and BC is 3 times KB. Area of rect ABCD is 94 cm2 and the area of triangle KGB is 6 cm2.

Find the area of triangle KEL.
Can anybody tell me how to draw the diagram here?
This qn can be found on the last page of My pals are here workbook 5A.
Thanks

[CJM]

blessedami:

CJM:

hi all,


need your expertise on this...

Susan wants to buy 7 dolls which are selling at the same price. However, she needs another $11.40 in order to buy them.
She then decides to buy 3 dolls instead and and $20.20 left after that. What is the cost of each doll ?

cheers..

My DS got this answer:

7-3=4
$20.20+$11.40=$31.60
$31.60/4= $7.90

Mathsguru/Dharma- please correct him if he is wrong

thank you for the answer !!
ur ds is so smart ... how old is he?

[firebird]

Dear blessedami


Good evening.

I am very very sorry for posting an incomplete and incorrect question.

I apologise for my mistake.

The question is :

An equal number of girls and boys went to a party.
The ratio of the number of girls who wore spectacles to the number of boys who wore spectacles was 11 : 3. The ratio of the number of girls who did not wear spectacles to the number of boys who did not wear spectacles was 3:5.

a) Find the ratio of the number of boys who wore spectacles to the number of boys who did not wear spectacles.

b) There were 7 time as many girls as boys who left the party. The ratio of the number of girls to the number of boys who remained at the party became 35:38. If there were 560 girls remaining at the party, how many girls left the party?

Thank you
firebird