Tutor MathsGuru: Ask me for your burning Maths questions!

[ChiefKiasu]

mathsguru:

Hi everyone,


My sincere apologies for not being active the past couple of weeks. Was down with a bad strain of flu towards the end of 2009 and was away on a holiday and now I'm back in action...ha! (but unfortunately, the flu bug decided to pay me a visit yet again...so i started 2010 with a *sneeze* and *cough*...urghhh!!)

Anyway, stayed up the whole night to do up all the outstanding solutions...hopefully, they make sense and can help you all when you explain to your DS/DD...

Will upload them accordingly in the next few posts. If you need clarification, pls feel free to shout! Hehe...

And before I forget, here's wishing everyone in KiasuParents.com a Happy 2010!! May all hard work reap deserving results!!

Cheers,
MathsGuru

Thanks mathsguru for your hardwork! A most happy, healthy and properous 2010 to you too!

[KSP]

Thanks, mathsguru. You are marvellous!!!

mathsguru:

Hi KSP,

Here are my solutions. These are typical primary school questions which are best solved using models/diagrams. I'm not surprised why the banker cannot solve most of them... Just like most of us adults, we tend to think too much and fail to look at the questions from another angle.

Hope the solutions help!

Cheers,
MathsGuru

[YLH88]

Hi mathguru,


Thank you for the solution. I will look through again and let you know which part. I just find the sweet and chocolate changing of the ratio and parts very confusing.

Hope you recover soon !!

Thank you so much for your help!

Regards

[pineapple tarts]

Hi Mathsguru,


Many thanks for the solutions. & pls take care. I still have a lot of questions to ask keee..... :oops:

[YLH88]

Hi mathsguru,


http://www.postimage.org/image.php?v=Pq1eShZA
In the above question,
1) the 2th and 4th diagram are referring to Andrew's model right ?
2) how did you get the step 4 x (12 + 18) ?


http://www.postimage.org/image.php?v=aV10Xmt9
For the chocolate and sweet question, I do not understand the 3rd row from the last upwards, ie
1) how do you get Jim's choc : sweet = 7u : +1p and Kim's choc : sweet = 7u : -1p ?

from that row upwards, I lost liao ...

Hi Dharma,

The answer for the marble question is 168, not 132 leh. is there any steps not correct ? Also I do not understand how you get 9 units - 270 = 3 units + 30 ?

I am trying to understand the 2 different methods use to solve the marble question, so sorry got to ask both Dharma and Mathsguru for help !!! :?:

Thank you very much!!

[Dharma]

YLH88:

Hi mathsguru,


http://www.postimage.org/image.php?v=Pq1eShZA
In the above question,
1) the 2th and 4th diagram are referring to Andrew's model right ?
2) how did you get the step 4 x (12 + 18) ?


http://www.postimage.org/image.php?v=aV10Xmt9
For the chocolate and sweet question, I do not understand the 3rd row from the last upwards, ie
1) how do you get Jim's choc : sweet = 7u : +1p and Kim's choc : sweet = 7u : -1p ?

from that row upwards, I lost liao ...

Hi Dharma,

The answer for the marble question is 168, not 132 leh. is there any steps not correct ? Also I do not understand how you get 9 units - 270 = 3 units + 30 ?

I am trying to understand the 2 different methods use to solve the marble question, so sorry got to ask both Dharma and Mathsguru for help !!! :?:

Thank you very much!!

Hi YLH88,

I’ll answer the marbles qn first. You’re right, about 168. I found total for Andrew instead of Kenny. The working has been amended.

About 9 units – 270 = 3 units + 30
This is from the 2nd condition where Andrew gives 12 marbles to Kenny, Andrew will have 1/9 of the marbles Kenny has.

So, finally Kenny will have 3 units + 30 and Andrew will have 1unit – 30

Kenny : 9 parts = 3 units + 30
Andrew : 1 part = 1unit -30

So, if Andrew has 9 parts, he will have 9 units – 270

Equate the two 9 parts to solve.


http://www.postimage.org/image.php?v=Ts1U5SQ0

[Dharma]

YLH88:

Hi mathsguru,


http://www.postimage.org/image.php?v=Pq1eShZA
In the above question,
1) the 2th and 4th diagram are referring to Andrew's model right ?
2) how did you get the step 4 x (12 + 18) ?


http://www.postimage.org/image.php?v=aV10Xmt9
For the chocolate and sweet question, I do not understand the 3rd row from the last upwards, ie
1) how do you get Jim's choc : sweet = 7u : +1p and Kim's choc : sweet = 7u : -1p ?

from that row upwards, I lost liao ...

Hi Dharma,

The answer for the marble question is 168, not 132 leh. is there any steps not correct ? Also I do not understand how you get 9 units - 270 = 3 units + 30 ?

I am trying to understand the 2 different methods use to solve the marble question, so sorry got to ask both Dharma and Mathsguru for help !!! :?:

Thank you very much!!

Hi YLH88,

Now the choc & sweets qns

1.\tStart from the bottom of the schedule and work backwards/upwards.
2.\tYou know the end condition (i.e. ratio of choc : sweets of Jim and Ken had finally which are 7:1 and 4:1 ) – given in the qns.
3.\tKen bought some sweets and gave half of it to Jim. So, if Ken had 1p sweets at the end, he must have bought 2p sweets and gave 1p sweets to Jim. Look at right most column under Ken (Sweets) you find 2p -1p = 1p.
4.\tSimilarly, under 2nd column, Jim (Sweets) , you add 1p sweets. This is the no. of sweets Jim received from Ken.
5.\tJim ate 12 sweets (so minus 12 in 2nd column) and Ken ate 18 chocs (minus 18 in 3rd column).
6.\tNow, looking at the 1st sentence of Qn, Jim bought some chocs and gave half of it to Ken.
7.\tSo, if Jim had 7u chocs at the end, he must have bought 14u chocs and gave away 7u chocs to Ken. Look at Column 1; you get 14u -7u = 7u. The minus 7u chocs shows the no. of chocs given by Jim to Ken.
8.\tNow look under Column 3, you have +7u. This shows the no. of chocs that Ken received from Jim.
9.\tFinally, we get 2 equations (Under Column 2; 1p – 12 = 1u and under Column 3; 7u – 18 = 4p)
10.\tSolve the 2 equations to get the answer.

[sachiko]

Thank you, Mathsguru. Greatly appreciate your help.


Wish you a joyful and healthy 2010!

mathsguru:

sachiko:

Hi

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

Thank you

Hi Sachiko,

Here are my solutions.

http://www.postimage.org/image.php?v=Ts1QRA4S

http://www.postimage.org/image.php?v=Ts1QRxAJ

Cheers,
MathsGuru

[headache]

Question : FRom his pocket money, Victor spent thrice the amount that he could save every month. When he spent $20 less, he found he could save $40. How much was his pocket money?


Thank you Maths Guru!

[YLH88]

Hi Dharma,


Thank you very much for the help! I will look through the steps again