Tutor MathsGuru: Ask me for your burning Maths questions!

[Tang]

Daddy:

Thanks to all,


Hi Tang,

I do not understand this statement in bold.

Box --> 5/4 x 0.07 = 0.0875 kg
Box + 1 doll --> 0.0875 + 0.07 = 0.1575 kg.

Hi,

Given question:

A box contains 30 similar dolls. The total mass of the box with 3/5 of its contents is 0.84Kg lighter than the box with all its contents. The mass of each doll is 4/5 times the mass of the box. Find the total mass of the box and a doll. ( Give your answer in Kilograms).


The mass of each doll is 4/5 times the mass of the box. -- So the mass of the box is 5/4 times the mass of each doll.

[Vanilla Cake]

clblinym:

Dear Parents,

please help me solve the following Math question for my DS.
I have no idea how to solve and the answer was not given.
Thanks in advance.
Regards,
Amy
http://www.postimage.org/image.php?v=aV2Ofii

This question was from Singapore Mathematical Olympiad for Primary Schools 2004 - Q26.

[Vanilla Cake]

James Ang:

A few questions to share with the \"students\" here.

James Ang:

Q2)The Sentosa High School's telephone number is an eight digit number.The sum of the two numbers formed from the first three digits and the last five digits respectively is 66558.The sum of the two numbers formed from the first five digits and the last three digits is 65577.Find the telephone number of the The Sentosa High School.

Source: Singapore Mathematical Olympiad for Primary Schools 2004 - Q29.

James Ang:

Q3)Placed on a table is a maths problem
89+16+69+6X+Y8+88
X and Y represents a digit.
Two students A and B sit on the opposite sides of the table facing each other.They read the problem from their directions and both get the same answer.What is their answer?

Source: Singapore Mathematical Olympiad for Primary Schools 2004 - Q16.

[Vanilla Cake]

clblinym:

Hi, Parents


Can anyone help solve the following math question. Many thanks.

The answer given is 5:2.

Amy
http://www.postimage.org/image.php?v=aVi95Tr

Source: Singapore Mathematical Olympiad for Primary Schools 2005 - Q24.

[Vanilla Cake]

Bommu99:

Hi Mathsguru,


Would greatly appreciate your help to solve these 2 questions which are among the SMOPS sample questions.

Thanks,

Bommu99
http://www.postimage.org/image.php?v=gx11D_jS

Source: Singapore Mathematical Olympiad for Primary Schools 2007 - First round - Q1 and Q3.

[Muffins]

Hi guys, do you have a quick way of doing this???


Thanks!

Grandma sent Johnny some money for his birthday. Johnny spent all of it in five stores. In each store, he spent $1.00 more than half of what he had when he came in. How much money did he get from grandma?

[iFruit]

Muffins:

Hi guys, do you have a quick way of doing this???


Thanks!

Grandma sent Johnny some money for his birthday. Johnny spent all of it in five stores. In each store, he spent $1.00 more than half of what he had when he came in. How much money did he get from grandma?

Can be done backwards way..

Amount he had when he came into 5th store = $2 (since 1 dollar more than half is all he has)
Amount he had when he came into 4th store = (2+1)2 = 6 (as he spent $1 more than half in 4th store leaving $1 less than half for 5th store)

Amount he had when he came into 3th store = (6+1)2 = 14

Amount he had when he came into 2th store = (14+1)2 = 30

Amount he had when he came into 1th store = (30+1)2 = 62


Money he got from grandma = $62

HTH

[Vanilla Cake]

Q1

Teams X and Y work separately on two different projects.
On sunny days, team X can complete the work in 12 days while team Y needs 15 days.
On rainy days, team X's efficiency decreases by 50% while team Y's efficiency decreases by 25%.
Given that the two teams started and ended the the projects at the same time, how many rainy days are there?

Q2
2004 students arrange themselves in a row.
In the first round of counting, they number themselves
1,2,3,1,2,3,1,2,3,........ from left to right.
In the second round of counting, they number themselves
1,2,3,4,5,1,2,3,4,5,1,2,3,4,5........ from right to left.
Find the number of students whose sum of numbers in the first and second rounds of counting is 5.

Q3
Tom walks up a staircase.
Each time he can either take one step or two steps.
How many ways are there for Tom to walk up a ten-step staircase?

Q4
Two points A and B are 1100 m apart.
Alice and Ben leave point A at the same time and travel to and fro along a straight road between A and B at uniform speeds. Alice and Ben travel at 60 m/min and 160 m/min respectively. They both stop after 40 minutes.
(i) At which meeting are they nearest to point B?
(ii) Find the nearest distance in metre.

Source: Asia Pacific Mathematical Olympiad for Primary Schools 2004.

Sorry, I could not find the given answers for the above questions. Your effort and time to provide worked solutions for them are appreciated.

[Muffins]

iFruit:

Muffins:

Hi guys, do you have a quick way of doing this???


Thanks!

Grandma sent Johnny some money for his birthday. Johnny spent all of it in five stores. In each store, he spent $1.00 more than half of what he had when he came in. How much money did he get from grandma?

Can be done backwards way..

Amount he had when he came into 5th store = $2 (since 1 dollar more than half is all he has)
Amount he had when he came into 4th store = (2+1)2 = 6 (as he spent $1 more than half in 4th store leaving $1 less than half for 5th store)

Amount he had when he came into 3th store = (6+1)2 = 14

Amount he had when he came into 2th store = (14+1)2 = 30

Amount he had when he came into 1th store = (30+1)2 = 62


Money he got from grandma = $62

HTH

Thanks iFruit, I had gotten it via this method as well, but just wanted to find whether there was a quicker way of doing this

[iFruit]

Vanilla Cake:

Q1

Teams X and Y work separately on two different projects.
On sunny days, team X can complete the work in 12 days while team Y needs 15 days.
On rainy days, team X's efficiency decreases by 50% while team Y's efficiency decreases by 25%.
Given that the two teams started and ended the the projects at the same time, how many rainy days are there?

Amount of work done by Team X on sunny day = 1/12
Amount of work done by Team X on rainy day = 1/2 x 1/12 = 1/24

Amount of work done by Team X on sunny day = 1/15
Amount of work done by Team X on rainy day = 3/4 x 1/15 = 1/20

Suppose it took s sunny days and r rainy days to finish project.

Then

s/12 + r/24 = s/15 + r/20

(2s+r)/24 = (4s+3r)/60 -----> (2s+r)/2 = (4s+3r)/5 --> 10s + 5r = 8s + 6r ---> 2s = r

we also know s/12 + r/24 = 1 (total work)

so s/12 + 2s/24 = 1 --> s= 6

so rainy days = 12