Tutor MathsGuru: Ask me for your burning Maths questions!

[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.

[mathsguru]

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.

Hi OK Lor,

Here's my solution!

Hope it helps,
MathsGuru

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

[OK Lor]

mathsguru:

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.

Hi OK Lor,

Here's my solution!

Hope it helps,
MathsGuru

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

Hi MathsGuru,

Nice work, thanks.