Tutor MathsGuru: Ask me for your burning Maths questions!

[mathsguru]

kitty2:

1)During a telematch,each group was supposed to collect as many coloured balls as possible.Each colour represents a certain point as followed


red 2 points
green 5 points
blue 3 points

Within each container,the number of red balls was 20% more than the number of blue balls and 10% lesser than the number of green balls.Given that the total possible points if the group managed to collect all the balls was 724 points,how many red balls were there?

2) Jason had 75% as many stickers as Susan.After Jason and Susan bought another 48 stickers and 4 stickers respectively,Jason had 20% more stickers than Susan.How many stickers did Jason have at first?

3)Amos had 20% more sweets than Daniel.Amos started by giving 30% of his sweets to Daniel.Daniel in return gave 25% of his sweets to Amos.In the end.Daniel had 32 lesser sweets than Amos.How many sweets did Amos have at first?

Hi Kitty2,

Sorry for the delayed response, been pretty occupied over the weekend...Anyway, here are my solutions.

In my examples, you will see that I actually have decimal numbers for my no. of units in Qn 2 & 3. It doesn't matter, cos it's all proportion. As long as the amount for 1 unit is a whole no. (as the question deals with items that require whole no.s e.g. stickers, etc), it means your calculation should be correct. I thought this is easier than trying to find the LCM for Questions 2 & 3.

Let me know if you need clarification ya...

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

http://www.postimage.org/image.php?v=PqeCCw9

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

Cheers,
MathsGuru

[kitty2]

:thankyou: mathsguru

[KSP]

Hi mathsguru,


Have you tried doing the questions posted in \"Are you smarter than a PSLE Kid\" at http://www.blogtv.sg ? (http://blogs.blogtv.sg/starbloggers/2009/10/23/math-quiz/
10 questions, 40 minutes later, the 12-year-old boy emerged triumphant, having answered 4 questions correctly. The 31-year-old banker managed only 1 correct question. So do you think you’re smarter than a 12-year-old? Here are the 10 questions we posed to our two wonderfully brave contestants.)

Here are the questions and answers. It will be very helpful if you can show us the working. Thank you in advance.

QUESTION 1
Bryan invited 20 more boys than girls to a party. 3/4 of the boys and 2/3 of the girls came. 19 people didn’t come. How many people did he invite?



QUESTION 2
Of the visitors in a museum, 40% are children, 3/4 of the adults are women.
a) what is the ratio of children:men:women.
b) the second day, children number increased by 20%, adults number remain the same but women is 3/5 of adult. if there are 336 more children than women, how many visitors on second day



QUESTION 3
The figure below, not drawn to scale is made up of a big circle, two semicircles, two quadrants and two squares.
a) Find the perimeter of the shaded figure
b) find the area of the shaded figure

http://www.postimage.org/image.php?v=aV61DoS


QUESTION 4
A millipede is climbing up a wall. For every 3cm it climbs, it slips by 1cm. It takes 3 seconds to climb 1 cm and 1 second to slip by 1cm.
a) How far would the millipede have climbed after 1 minute?
b) How long would the millipede take to climb 56cm?



QUESTION 5
There are red and green beads in a bag. When 75 green beads are added, the percentage of red beads decreased from 30% to 20%. How many red beads are there in the bag?



QUESTION 6
Kavita had 50% fewer erasers than Mark. After Mark gave 15 of his erasers to Kavita, Kavita had 40% fewer erasers than Mark. How many erasers did Kavita have at first?



QUESTION 7
The ratio of Ryan’s pocket money to John’s pocket money was 3 : 2. After Ryan saved $15 and John spent $8, the ratio of Ryan’s pocket money to John’s pocket money was 3 : 1. How much money did Ryan have at first?



QUESTION 8
Shop A has 156 kg of rice. Shop B has 72 kg of rice. After both shops sold an equal amount of rice, the ratio of rice that shop A has to shop B is 4:1. Find the amount of rice sold by each shop.



QUESTION 9
6/14 of the chairs in a hall are in rows of 13. Half of the chairs are in rows of 7. There are 112 more chairs in rows of 7. The rest of the chairs are stacked up. Find the total number of chairs.



QUESTION 10
Tank A is filled with water to its brim. Water is then poured from Tank A to Tank B until both share the same height. What is this height?


http://www.postimage.org/image.php?v=aV61KTi




Answers.

QUESTION 1
68 people were invited

QUESTION 2
a) 8:3:9
b) 3024 visitors

QUESTION 3
a) 125.6cm
b) 192.5cm squared

QUESTION 4
a) 12cm
b) 4min 36 sec

QUESTION 5
There are 45 red beads in the bag

QUESTION 6
Kavita had 120 erasers at first

QUESTION 7
Ryan had $39 at first

QUESTION 8
Each shop sold 44 kg of rice.

QUESTION 9
There were a total of 1568 chairs.

QUESTION 10
The height of the water is 25 cm.

[RedRedWine]

Hi mathsguru,


here’s another question, i can solve using algebra equation but don’t know how to explain to my son. Hope you can help.

Feng Rui has 225 more Singapore stamps than Malaysia stamps. After selling 3/5 of the Singapore stamps and 1/3 of the Malaysia stamps, he has 858 stamps left. How many stamps does Feng Rui have at first?

TIA.

[VitoRelax]

For the angle question in 2009 PSLE, can explain again how to derive that AD=AC=AB ?


Did the question said that it is the radii of an arc ?

Thanks

[Muffins]

Vikaesh:

Dear MathsGuru, i really admire your expertise in Mathematics. Could you be so kind as to share with me some of your Secondary one Express Notes of any subject....(all others could share note if you please)

P.S. : I understand if you do not want to share them with me...

Hey Vikaesh, just asking, what school did you get into?

[YLH88]

Hi mathsguru,


Need your help to solve the below 3 questions from P6 :?: . I know the last question has been solved in the forum, but I still don't quite understand.

1) If Kenny gives 18 marbles to Andrew, he will have thrice as many marbles as Andrew. If Andrew gives 12 marbles to Kenny, he will have 1/9 of the number of marbles that Kenny has. How many marbles does Kenny have at first ?

2) Mei and Lin took part in a cycling race. Mei cycled at a speed of 20 km/h. Both of them did not change their speed throughout the race. When Lin covered 1/2 the distance, Mei was 3.5 km in front of her. Mei reached the finishing line at 10.45 am. What time did Lin reach the finishing line ?

3) Jim bought some chocolates and gave half of them to Ken. Ken bought some sweets and gave half of them to Jim. Jim ate 12 sweets and Ken ate 18 chocolates. After that, the number of sweets and chocolates Jim had were in the ratio 1:7 and the number of sweets and chocolates Ken had were in the ratio 1:4. How many sweets did Ken buy ?


Thank you so much for your help !!

[sachiko]

Hi


I would appreciate if you could help me to solve the following questions:

1) Marcus, Joanna and Shawn had 48 stamps. Marcus had 10 more stamps than Joanna and 14 more stamps than Shawn. When Marcus gave some stamps to Joanna and Shawn, all of them had an equal number of stamps. How many stamps did Joanna and Shawn receive from Marcus?

2) Osman had $41 and Mike had $15. After each boy had bought the same textbook each at the bookshop, Osman had 5 times as much money as Mike. How much did the texbook cost?

Thank you

mathsguru:

Original Title: Let MathsGuru Answer Your Burning Maths Questions!

:welcome:

Dear Parents,

Are you frustrated/stuck when helping your child solve his/her Maths questions? Are you inclined to use Algebra most of the time? Do you have difficulty trying to use diagrams or other heuristic methods (that Primary School students learn) to solve?

:idea: Post your questions here and see how MathsGuru solve them to the best of her ability. Detailed solutions will be posted back in this thread.

So start asking and watch this space!!

Cheers :celebrate: ,
MathsGuru

P/S (Disclaimer, in case you're wondering...):
Although MathsGuru is a full-time Maths tutor, this thread is meant to be an absolutely free resource for parents (or even children) with no strings attached. Just someone who's passionate about Maths and wanna spread the fun in learning Maths with others.

[lizawa]

Hi Sachiko,


Not maths guru, but here's solution to q1:
http://farm5.static.flickr.com/4043/4246115761_f027f660bd.jpg\">

[lizawa]

Hi Sachiko, solution to question 2:

http://farm3.static.flickr.com/2718/4246924078_13bd639b35.jpg\">