Q&A - PSLE Math

[Ler]

tianzhu:

Ler:

Can you provide Uncle observer solution blog. website pertaining for the above exam paper.

Hi Ler

Just click on the links provided and they will lead you to the relevant websites.

Best wishes

Hi VC and tianzhu

I try that VC given the solutions (for abc parents), but could not access to the link but only provided the solution

Sorry VC, i seldom use computer, only touches this week only, still learning, may VC can help me to link to it. for uncle observation solution. May be can type out the website for me. I saw him draw model , i seems to understand more..... thanks.

Ler

[Dharma]

tianzhu:

kancheongmum:

RV 2010 Q28(ans 10Km/h)

Samad and Toby walked from Town A to Town B at the same time. Samad was faster than Toby by 4km/h . When Samad reached Town B, he immediately walked back to Town A. On the way back, he met Toby who was 10 km away from Town B. What was Samad's speed?

Hi kancheongmum

It appears that 10km/h is one of the answers you can have in this question. Is there any more information such as the distance Town A and B given in the question?

Best wishes

When Samad reached Town B in 4 hrs, is will be 16km ahead of Toby ( 4km/h x 4 hrs)

So when Samad turns back and moves toward Toby, they will meet at a point where Toby travels another 6km and Samad travels another 10km,

For 2 persons meeting/passing each other time taken is the same fir both if them

Speed ratio = Distance ratio
Since difference in speed ratio is 4km/h

Speed ratio = distance ratio => Samad : Toby = 10 : 6
Samad's speed = 10km/h

[tianzhu]

Ler:

Hi VC and tianzhu

I try that VC given the solutions (for abc parents), but could not access to the link but only provided the solution

Sorry VC, i seldom use computer, only touches this week only, still learning, may VC can help me to link to it. for uncle observation solution. May be can type out the website for me. I saw him draw model , i seems to understand more..... thanks.

Hi Ler

Here’s Observer blog
http://prischoolmaths.blogspot.com/

This is another good resource for PSLE students
http://road-to-psle.blogspot.com/

Best wishes

[tianzhu]

kancheongmum:

Hi Tianzhu I think the original question lack some information. The student added in \"When Samad reached Town Bin 4 hours[u]\" which I didn't type. I think with that info we can solve the problem.

Hi kancheongmum

Yes, if the additional information included in the question, the answer is 10km/h for Samad.

For them to meet at 10km away from Town B, they must meet at the fifth hour.

To check, the distance between towns is 40km,Samad’s speed is 10km/h and Toy’s speed is 6km/h.

Best wishes

[tianzhu]

kancheongmum:

My lst question I try to use Sally to check if I can get the correct answer. I think I miss out something. Can I say that when Alan take 3 hours for that part of the journey, Sally will take 3 x 3/2 = 4.5 hours?
For meeting, from opposite direction, must we get the 2 to move out at the same time?

Hi kancheongmum

Yes, you are correct to say 4.5h,she took another 1.5h for the remaining part of journey making a total time of 6h.

You are also spot on in your second point.

Best wishes

[kancheongmum]

Hi Tianzhu and Dharma

Thank you got all the info now.
one more question MCQ RV2010 Q12 (ans 43 yrs old)
The average age of Mr Lim"s family of 4 is 26years old. The total age of Shawn and Mr Lim is 2 years more than the total age of Mary and Mrs Lim. How old is Mr Lim?

for algebra question if the work out answer is (168 - x)/2 + x
do the student leave the answer this way or has to simplified further to
84 + 1/2 x

[tianzhu]

kancheongmum:

one more question MCQ RV2010 Q12 (ans 43 yrs old)
The average age of Mr Lim\"s family of 4 is 26years old. The total age of Shawn and Mr Lim is 2 years more than the total age of Mary and Mrs Lim. How old is Mr Lim?

Hi

As this is an MCQ, what are the other available options?

Best wishes

[tianzhu]

kancheongmum:

for algebra question if the work out answer is (168 - x)/2 + x
do the student leave the answer this way or has to simplified further to
84 + 1/2 x

Hi

If I remember correctly, algebra is not thoroughly covered in P6.

I suggest you ask your boy to check with his teacher.

Best wishes

[Dharma]

kancheongmum:

for algebra question if the work out answer is (168 - x)/2 + x
do the student leave the answer this way or has to simplified further to
84 + 1/2 x

Hi kancheongmum,

You will need to simplify the answer to 84 + x/2

[CTong]

Pls help to solve:


James had 20 goldfishes and 30 guppies in a fish tank. 20% of the guppies died. James bought another 16 goldfishes.
a) What percentage of the fish were guppies?
b) What was the increase in percentage of goldfish?