Tutor MathsGuru: Ask me for your burning Maths questions!

[mathsguru]

sachiko:

Hi MathsGuru


Can you please help me with the following Maths questions? They look very simple but I just can't figure out the answers:

1. Mandy spent 4/5 of his money on 12 oranges and 4 pineapples. If one orange costs twice as much as a pineapple, how many pineapple could he buy with the rest of the money?

2. A highlighter costs 3 times as much as a marker. Bert spent 2/5 of his money on markers and 1/3 of the remainder on a pen. The highlighter cost $0.90. How many markers did he buy?

Thank you.

Hi Sachiko,

Here are my solutions.

However, I have a query on Question 2. I thought the question seems a little unusual because of the sudden mention of the \"pen\". In my solution, I've assumed that it's a typo and the \"pen\" actually refers to the highlighter.

I guess another way of interpreting is to assume that there is really a pen and the rest of the money is spent on the highlighter which is not apparent in the question.

In any case, for both scenarios, they can be solved without the use of the highlighter's price.

Cheers,
MathsGuru

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

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

[mathsguru]

pandan:

Hi all,


My problem is somehow solved after I rebooted my pc. thank you.

Hi Pandan,

Glad that you managed to \"resolve\" the issue! It happens to me sometimes too...but I'm no IT expert...dunno how to solve it. I will just restart my browser and access the site a while later...haha!

Cheers,
MathsGuru

[mathsguru]

firebird:

Dear mathsguru


Good morning.

Please help me on the following maths:

1) A man travels from Town X to Town Y at 4 Km/h and from Town Y to Town X at 6 Km/h via the same route. The whole journey takes 45 minutes. Find the distance from Town X to Town Y.

Given answer 1.8 Km, however my answer is 1.875 km.

2) A pen costs 40 cents more than a ruler. John paid $x for a pen and a ruler. Find the cost of a ruler in cents.

Given answer is (50-20)cents

3) A Spaceship lego set cost $80 more than a Tommy train set at a toyshop. During its anniversar, a storewide 20% discount was given to all customers. In addition, members of the toyshop enjoy an addtional 10% discount. Mr. Tan, a member of the toyshop, paid a total of $345.60 for the Spaceship lego set and the Tommy train set. Calculate the original price of the Spaceship set.

Given answer is $28

4) Mr. Tan took 6 hours to drive from Town A to Town B.
Mr. Lim, who started at the same time as Mr. Tan, took 4 hours to drive from Town B to Town A. When they meet each other, they were 48 km from the midpoint of Town A and Town B.
(a) Calculate the distance between Town A and Town B.
(b) Calculate the speed of Mr. Tan.

5) 20% of John's saving is $120 more than 30% of Brian's savings. After John spent 5/6 of his savings and Brian spent 1/2 of his savings, John has $20 more than Brian. Find the saving of John at first.

Many thanks
firebird

Hi Firebird,

Here're my solutions. Hope they will help you and your child gain a better understanding of speed and % questions!


MathsGuru

http://www.postimage.org/image.php?v=gxtyZ39

http://www.postimage.org/image.php?v=gxtz0yi

http://www.postimage.org/image.php?v=gxtz32r

http://www.postimage.org/image.php?v=gxtz5xA

http://www.postimage.org/image.php?v=gxtyWz0

[firebird]

Dear mathsguru and vanilla cake


Good afternoon.

Many thanks for helping me.

With best regards
firebird

[sachiko]

Thanks MathsGuru,


The qn really has a pen. I was puzzled too. Anyway, my girl will check with her teacher to see if there is a typo error. Once again, thank you for your help.

[P5G]

sachiko:

Thanks MathsGuru,


The qn really has a pen. I was puzzled too. Anyway, my girl will check with her teacher to see if there is a typo error. Once again, thank you for your help.

Mr Sachiko,


I think Tang has already solved this question on 9 April and the answer is 3 markers. You may want to take a look at the workings.


Good night.

Workings by Tang

1 - 2/5 = 3/5

1/3 x 3/5 = 1/5

3/5 - 1/5 = 2/5

2 u --> $0.90 --- This is the amount spent on markers

1 highlighter --> $0.90

1 marker --> 1/3 x 0.90 = $0.30

0.90/0.30 = 3 markers

He bought 3 markers.

[starlight1968sg]

mathsguru:

Hi Starlight1968sg,


Sorry for the delay! Have been quite tied up this week.

Here're my solutions.

Cheers,
MathsGuru

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

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

Thanks so much MathsGuru and others who have helped in one way or another.

[OK Lor]

Hi MathsGuru


Good morning.

Ali, Bala and Charles shared a tin of cookies. Ali took 5/6 of the tin of cookies and 1/3 of a cookie. Bala took 5/6 of the remaining tin of cookies and 1/3 of a cookie. Charles received only 2 cookies. How many more cookies did Ali have than Bala?

Thanks.

[Guan Hui]

After Ali took the cookies.

Bala 5/6 of the remaining cookies and 1/3cookie and charles received the rest(2 cookie)

1-5/6=1/6 of the remaining cookie
(2+1/3) cookie = 1/6 of the remaining cookie
so the total amount of remaining cookie= (2 +1/3) x 6
= 14 cookies
No. of cookie Bala received= 14-2 =12 cookies

From the beginning
Ali 5/6 of total cookies and 1/3cookie
(14+1/3) cookie = 1/6 of total cookies
So the total amount of cookie= (14+1/3) x 6
= 86 cookies
No. of cookies Ali received= 86-14=72 cookies

How many cookies more? 72-12=60 cookies

[OK Lor]

Guan Hui:

After Ali took the cookies.

Bala 5/6 of the remaining cookies and 1/3cookie and charles received the rest(2 cookie)

1-5/6=1/6 of the remaining cookie
(2+1/3) cookie = 1/6 of the remaining cookie
so the total amount of remaining cookie= (2 +1/3) x 6
= 14 cookies
No. of cookie Bala received= 14-2 =12 cookies

From the beginning
Ali 5/6 of total cookies and 1/3cookie
(14+1/3) cookie = 1/6 of total cookies
So the total amount of cookie= (14+1/3) x 6
= 86 cookies
No. of cookies Ali received= 86-14=72 cookies

How many cookies more? 72-12=60 cookies

Hi Guan Hui,

Thanks.