http://i60.tinypic.com/2zrdenc.jpg\">

Hi

You see, Mensuration of Pyramids always have to relate with other topics. In this case, it is Pythagoras theorem @Kiasulormee

2Transformer:

http://i41.tinypic.com/2v32bsy.jpg\"> Pls help to solve this question....... TIA

Hi
This question uses some factorisation and knowledge of fractions.
FIRST, make the numerator of 3/10 and 40% the same since the question says that they are the same.
So,in this case,
6/20,6/15.
From here we can derive that area of triangle C is 15u and triangle A is 20u.
6u+6u=12U
Now,12U is 80% of the area of triangle b.
Thus,unshaded area of triangle b is -3U
Unshaded area of figure-
a-14
b-5
c-3
total-22U
Total area of figure-15+15+20=50u
ans:22/50
=11/25

2Transformer:

Pls help to solve the following questions :


Q1. Hamid had 5/7 as much money as his sister. After each of them had spent $154 on some game cartridges, Hamid had 7/12 as much money as his sister. How much did his sister have at first?

Q2. In a school hall, a certain number of desks can be arranged in exactly 15 desks per row. When the same number of desks is arranged in 12 desks per row, there will be 4 more rows and 9 desks left over. How many desks are there altogether?

Q3. 32% of Jane's sum of money is equal to 3/4 of Omar's sum of money. If they have a total sum of $642, how much does Omar have?

Q4. Tom, Jaya and Muthu had some amount of grapes each. If Tom gave Jaya 864g of grapes, Tom and Jaya will have an equal amount of grapes. If Jaya gave 864g of grapes to Tom, he would have 1/4 of what Tom had. Muthu's amount of grapes is the total amount of grapes of the other two boys. How many kilogrammes of grapes did they have altogether?

TIA

Q3.32%=8/25
Make the numerator equal
24/75,24/32
32y+75y=107y
107y=642
y=642/107
=6
Omar-32y-6x32
=$192

MommyDearest:

MommyDearest:

http://i45.tinypic.com/rksmfn.jpg\">


Qtn quoted here for better visibilty.

<<Shawn wanted to find out how much force was needed to overcome the attraction of different materials which were attracted to a strong magnet. The materials are of similar size. He set up the experiment as shown below.

(see image above)

He pulled on the spring balance until the material was separated from the magnet. The readings on the spring balance were recorded as shown below.

Material-------->Readings on the Spring Balance (unit force)
P---------------->45
Q---------------->60
R---------------->30
S---------------->45

What conclusions could he make from the above readings ?

A: Q is the best material for magnetic attraction.
B: R is made from a heavier material than material Q.
P and S are made from the same magnetic material.
R is easier to be magnetized as compared to material P.

(1) A only
(2) B and C only
(3) A and D only
(4) A, B and C only >>

Can someone please advise on the answer for the above question ? Many thanks in advance!

Hi
The answer should be 1 as option b is telling that this experiment variable is the materials mass which is totally incorrect.Once b is false,2 and 4 are stroked off.So,to answer this question ,identify the independent variable in this experiment.
Charsen 2.0

AgonyMum:

charsen:

[quote=\"AgonyMum\"]Hi,question from Nanyang 2011 SA -

Which of the following human systems show an increase in activity when a person is running?
A muscular system
B respiratory system
C circulatory system

TIA!

All Three answers are correct.When the person is running,he inhales more air.
That means more food is needed from the digestive system to travel through the circulatory system.Then,more respiration happens at the lungs.Finally,the digested food would go to the muscular system to give energy for the person to run.
Charsen

Hi Charsen,
That was what my child wrote and I marked him correct.However, when I double-checked with the answer sheet provided, it was only circulatory and respiratory systems. Muscular system was not included. Do you know any reason why?
Thanks![/quote]Hi
I am so sorry.The answer is circulator system and respiratory system.The muscular system remains in activity as they DID NOT mention whether the person runs faster as time passes.So,the person should be running at a constant speed,in which the muscular system functions at a constant rate.
Hope my explanation works.
Charsen

dazzlego:

mathnoobs:

Hi Mathizzfun

I recently came across this problem and found that you have the answer. http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=7640


Abel and Ben can build a model aircraft together in 4 days. Ben and Calvin can do the same job together in 1 1/2 times as many days. Abel and Calvin can complete the same job together in twice the number of days Ben and Calvin can do together. If the three boys decide to work together, how long will they take to complete their job?
(Answer: 4 Days)

However, I don't quite understand this line:
Work needed to complete job --> 12 units

how do you get the 12 units ? thanks in advance.

I guess he assume that the number of work done is the LCM of 4, 6 and 12. Since A+B = 4 days, B+C = 6 days, A+C = 12 days

Hi
Dazzle go,your explanation is correct.

AgonyMum:

Hi,question from Nanyang 2011 SA -

Which of the following human systems show an increase in activity when a person is running?
A muscular system
B respiratory system
C circulatory system

TIA!

All Three answers are correct.When the person is running,he inhales more air.
That means more food is needed from the digestive system to travel through the circulatory system.Then,more respiration happens at the lungs.Finally,the digested food would go to the muscular system to give energy for the person to run.
Charsen

NY1969:

Hi, need help here. My gal has a problem that she kept forgetting stuff that was taught. We have sent her to courses like Mind Edge but didnt help much. The other problem isMaths. She merely memorised steps to solution but fail to understand the concepts. hence mostly end up wrong.


Will ginko helps?Any memory booster to advise? PSLE approaching....really need advise.

Hi
You can use Mind maps to summerise the stuff she has been taught in school.
For Maths you should go through with her some problems.Ask her to understand the problem.It is not nesscary to memorise the problems.The key is to use the concepts learnt to solve the questions.One way is to ask your child of what is the problem in the question.Then,use the mind maps to find the concept.
Charsen.

Verysuperkiasu:

I have a question abt speed.


If the question states the motorist moving from one point to another at a certain speed, then rest for sometime, for example 40min. Then he continue journey for 2nd half.

If the question asks the average speed for 2nd half, do we take into account the 40 min? What if the question asks for the average speed for entire journey , then do we take time taken as inclusive of the 40min rest time?

Hi
If the question says that the resting time is 40 min,then you should not take that into account as the time taken to travel the second half is the time taken to drive the second half.
Charsen

Jamesbond:

Hi Have another doubt...


If salt is added to ice, how will it affect the melting point and freezing point...Can somebody give me the answer...

If I am correct...the melting point is lowered...

Also...when salt is added to ice, will the ice melt faster or slower?

Pl help...

Hi
You are correct.The melting point and the freezing point is lowered.It is a good thing as this concept may be tested on a application question.For example,in winter,many countries would sprinkle salt on almost everywhere if the environment is covered mostly in snow.Then,they would ask why the people in those countries do that.Now,that invovles this concept of lowering down the freezing point and the melting point of ice when salt is sprinkled on it.
Charsen