Tutor MathsGuru: Ask me for your burning Maths questions!

[mathsguru]

YLH88:

Hi Mathsguru,


With ref to the following question posted by Firebird, how did you derive the shaded are is 420 cm2 ?

Question 11) In the figure below, not drawn to scale, PQRS is a rectangle with a length of 45 cm and a width of 22 cm. The area of te TUVW is 75 cm2. Find the ratio of the shaded area to the unshaded area.

http://www.postimage.org/image.php?v=Pq46L9A

Thank you very much!

p/s now my ds is practicing the school test paper and come across this question which I recalled you have helped solved the question, but hor, I don't really understand the solution

Hi YLH88,

Apologies! Now that I re-look at my solution, I made a few typos! Must be type till blur already!! Paiseh~~

Here's my corrected solution.

The key thing tested here in the question is the concept of shared base and height of triangles. Does your boy understand how to find the unshaded area (i.e. area of 2 triangles - TUVW)?


MathsGuru

http://www.postimage.org/image.php?v=PqiW1x0

[mathsguru]

starlight1968sg:

Hi mathsguru and others,

I need some help:
(1) P, T and V have 960 beads altogether. P gave some of her beads to T and the number of T's beads was doubled. Then T gave some of her beads to V and the number of V's beads was doubled. If the 3 girls had the same number of beads in the end, how many beads did P have at first.
(ans: 560)
How to solve it?

(2) Look at the pattern below:
Position Number
1st 1
2nd 2
3rd 3
4th 2
5th 3
6th 4
7th 3
8th 4
9th 5
10th 4
11th 5
12th 6
(a) At what position does the number 12 first appear?
(b) What is the sum of the first 32 numbers?

(ans: (a) 30th, (b) 218)

For (a), do we simply write from position 12th till position 30th ie when we first see the number 12?

For (b), the calculations is too lengthy. Is there a method or a pattern one can recognise to simplify the calculation?

MTIA.

Hi Starlight1968sg,

Here're my solutions. Hope they are clear enough!


MathsGuru

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

http://www.postimage.org/image.php?v=Pqj2b_S

[mathsguru]

Daddy:

Hi mathsguru and others,


I have one difficult question. Pls help thanks. :?

1. IF Vaness gave 12 badges to Jay, both of them would have the same number of badges. If Jay gave 24 badges to Vaness, Vaness would have 5 times as many badges as Jay. How many badges did Vaness have?

Thanks alot
Daddy

Hi Daddy,

Here's my solution!


MathsGuru

http://www.postimage.org/image.php?v=aV7D79S

[mathsguru]

Jolyn:

Hi Maths Guru


I have a few questions and appreciate if you could help:

1. There are 38 red beans and 3 times as many blue beans in a box. How many blue beans are there in 4 such boxes?

2. The florist sold 4 times as many roses as tulips on Valentine's Day. If she sold 260 roses and day, how many roses did the florist sell?

Thank you very much....

Hi Jolyn,

Here're my solutions. I took the liberty to correct the typo in Question 2. Hope it's correct!


MathsGuru

http://www.postimage.org/image.php?v=aV7FxjA

http://www.postimage.org/image.php?v=aV7FzOJ

[mathsguru]

Daddy:

Hi mathsguru and others,


Thousand thanks to all that had answered my questions.

Another question:

1. The movie tickets sold on Thursday were 2/3 of the tickets sold on Friday. The tickets sold on Friday were 3/5 of the tickets sold on Satursday. If there were 380 movies tickets sold altogether. How many more tickets were sold on Satursday than on Thursday. :oops:

Thanksss.

Hi Daddy,

Here's my model solution.


MathsGuru

http://www.postimage.org/image.php?v=Pqj7ZaJ

[mathsguru]

Daddy:

Thanks Maths Monster & Vanilla Cake.


you all are thumb UP!!!!.

Sorry, One more question.

1. During an IT fair, for each book sold, Leena received a commission of $20. An additional bonus of $10 would be given to her for every 5 books sold.

a) How much would Leena receive if she sold a total of 12 books?
My ans:
1 book = $20
5 books = ($20x5) + $10= $110

15 books = 15 /5 = 3 of 5 books
= 3 x $110
= $330

b) How many books had she sold if she was given $8880?
???? help.

Is my Qa correct ?

Hi Daddy,

Here's my solution. Your answer to (a) is correct!

Cheers,
MathsGuru

http://www.postimage.org/image.php?v=aV7Igqr

[mathsguru]

firebird:

Dear maths guru


Good morning

Please help me on the following maths:

1) Susan saved $345 in $5, $10 and $50 notes. There were 35 notes althogether. She had 4 more $10 notes than $50 notes. How many $5 notes did she have?

2) Mr. Tan has some charity tickets. If he sends 4 tickets each to some companies, he will need 20 more tickets. However, if he sends 3 tickets each to the same companies, he will have a remainder of 50 tickets. How many tickets does he have.

3) Alex, Boon Kheng and Casmuri paid for a meal. Alex paid 1/5 of the amount Boon Kheng and Casmuri paid together, Boon Keng paid 1/4 of the amount Alex and Casmuri paid.

a) What fraction of the total cost of the meal did Casmuri pay?
b) If the meal cost $205.20, how much did Alex pay?

Thank you
firebird

Hi Firebird,

Here are my solutions. Questions 2 & 3 are rather popular questions in tests/exams, so must make sure your child understand how to tackle them!

Cheers,
MathsGuru

http://www.postimage.org/image.php?v=Pqjfl7i

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

http://www.postimage.org/image.php?v=Pqjfq6A

[mathsguru]

Brenda10:

Good afternoon Mathsguru and others,


I need help for the following P5 SA1 Q11. :?

Mrs. Sham had 4 times as many lollipops as chocolate bars. After giving 177 lollipops and 25 chocolate bars to her students, she had thrice as many chocolate bars as lollipops left. How many lollipops and chocolate bars did she have altogether at first?
(Given answer: 230)

Thank you for your help.

Hi Brenda10,

Here's my solution.

Cheers,
MathsGuru

http://www.postimage.org/image.php?v=TsHx97S

[mathsguru]

chrisho:

2 simple questions that need to find better way to explain to my son. d


1. James had twice as many marbles as Bob. After James lost 240 marbles, Bob had 3 times as many marbles as James. How many more marbles did James have Than Bob at first.

2.Peter is 8 years old and his mother is 30 years older than he. how old will Peter be when his mother is thrice his age?

TQ

Hi Chrisho,

Here are my solutions. Hope your son can understand them!

Cheers,
MathsGuru

http://www.postimage.org/image.php?v=aV7StYi

http://www.postimage.org/image.php?v=aV7Swsr

[mathsguru]

JayT:

Is it possible to solve the question below by models? Thanks, Mathsguru for setting up this thread!


In the begining, the ratio of Alan's marbles to Kevin's marbles was 3:4. After Alan bought another 9 marbles and Kevin lost 18 marbles, the ratio becomes 3:2. find the number of marbles Alan had at first.

Hi JayT,

Here's the model solution. Hope it helps!


MathsGuru

http://www.postimage.org/image.php?v=TsHBWX9