Q&A - PSLE Math

[Dharma]

tianzhu:

Hi Dharma


It's 30 minutes.

Life can be drastically changed in a matter of seconds not even minutes.

Best Wishes

Just by using the right strategy, you've saved the 4 guys

[Vanilla Cake]

Hi,

I am Pandan Cake (VC's younger sister) using her ID to post 3 rate questions and 1 speed question. Need your time and help to solve them so that I can forward them (solutions) to one of my elder cousins (a P6 boy) who is taking PSLE this year. Thanks in advance.
:please:

Q1
Desmond takes 9 days to renovate 1 kitchen while Philip takes 21 days to renovate the same kitchen. If Philip starts renovating the kitchen first and leaves the rest to be completed by Desmond, they will take 13 days in total to complete renovating the kitchen. How many days does Desmond spend on the job?

Q2
When Katie spent 1 day and Mia spent 2 days painting, they would paint 11/12 of a house. On the other hand, when Mia spent 5 days and Katie spent 2 days painting, they would paint 2 & 1/6 houses. How long will each of them need to paint 1 whole house by themselves?

Q3
When Caleb spent 2 days and Ethan spent 3 days assembling computers, they produced 42 sets of PCs. When Caleb spent 4 days and Ethan spent 2 days assembling computers, they produced 44 sets of PCs. How long will each boy require to assemble 30 sets of computers?

Q4
Nicholas and Oliver started driving from the same point but in the opposite directions round a 15 km circular track. Nicholas took 10 minutes t o complete each round. The two drivers met each other after 6 minutes. (a) At what speed where Nicholas ands Oliver driving at ? Give your answer in km/h. (b) How many rounds would each driver have completed when they met each other at the starting point for the second time ?

[Dharma]

Vanilla Cake:

Hi,

I am Pandan Cake (VC's younger sister) using her ID to post 3 rate questions and 1 speed question. Need your time and help to solve them so that I can forward them (solutions) to one of my elder cousins (a P6 boy) who is taking PSLE this year. Thanks in advance.
:please:

Q1
Desmond takes 9 days to renovate 1 kitchen while Philip takes 21 days to renovate the same kitchen. If Philip starts renovating the kitchen first and leaves the rest to be completed by Desmond, they will take 13 days in total to complete renovating the kitchen. How many days does Desmond spend on the job?

Earlier mistake corrected

http://www.postimage.org/

[Dharma]

Vanilla Cake:

Hi,

I am Pandan Cake (VC's younger sister) using her ID to post 3 rate questions and 1 speed question. Need your time and help to solve them so that I can forward them (solutions) to one of my elder cousins (a P6 boy) who is taking PSLE this year. Thanks in advance.
:please:

Q2
When Katie spent 1 day and Mia spent 2 days painting, they would paint 11/12 of a house. On the other hand, when Mia spent 5 days and Katie spent 2 days painting, they would paint 2 & 1/6 houses. How long will each of them need to paint 1 whole house by themselves?

http://www.postimage.org/

[Dharma]

Vanilla Cake:

Hi,

I am Pandan Cake (VC's younger sister) using her ID to post 3 rate questions and 1 speed question. Need your time and help to solve them so that I can forward them (solutions) to one of my elder cousins (a P6 boy) who is taking PSLE this year. Thanks in advance.
:please:


Q3
When Caleb spent 2 days and Ethan spent 3 days assembling computers, they produced 42 sets of PCs. When Caleb spent 4 days and Ethan spent 2 days assembling computers, they produced 44 sets of PCs. How long will each boy require to assemble 30 sets of computers?

http://www.postimage.org/

[Dharma]

http://www.postimage.org/


Hope these are useful. Good luck

[tianzhu]

Hi Dharma


Is LCM taught to your daughter in school?I don’t really find LCM mentioned in the textbooks.

So I wonder if this is an acceptable method to be used in primary maths?The other alternative is to use listing which is more tedious.

I remembered seeing my boy’s ws where the teacher made some comment to ask him for some explanation for an almost similar type of question.His method is pretty similar to that of LCM.The method used by his school in this particular instance is listing.

From the past years question in PSLE handbook(some questions may be excluded), I’ve yet to see a speed question on circular motion, so sometimes, I wonder whether or not it is in the syllabus.

[turquoise]

Dharma:

These are 2 good qns on rates


2)Tom started work on a job for 30 days. Jerry continued the job alone for another 5 days and finally they worked together for another 10 days to complete that job.For the same job, if Tom and Jerry work together, they can complete it in 20 days.Assuming Tom and Jerry each work at a constant rate throughout, how many days will Tom take to complete that job alone?

Dharma, how do you solve this question? Thanks.

[Dharma]

tianzhu:

Hi Dharma


Is LCM taught to your daughter in school?I don't really find LCM mentioned in the textbooks.

So I wonder if this is an acceptable method to be used in primary maths?The other alternative is to use listing which is more tedious.

I remembered seeing my boy's ws where the teacher made some comment to ask him for some explanation for an almost similar type of question.His method is pretty similar to that of LCM.The method used by his school in this particular instance is listing.

From the past years question in PSLE handbook(some questions may be excluded), I've yet to see a speed question on circular motion, so sometimes, I wonder whether or not it is in the syllabus.

I am not sure Tianzhu whether it was taught in school. Think my girl learnt it from her sis.

Don't worry too much abt method. If u are comfortable w/ a particular method, then use it.

For circular motion - good to know (was tested in enrichment ws in rgps)

[Dharma]

turquoise:

Dharma:

These are 2 good qns on rates


2)Tom started work on a job for 30 days. Jerry continued the job alone for another 5 days and finally they worked together for another 10 days to complete that job.For the same job, if Tom and Jerry work together, they can complete it in 20 days.Assuming Tom and Jerry each work at a constant rate throughout, how many days will Tom take to complete that job alone?

Dharma, how do you solve this question? Thanks.

Hope this helps turquoise

http://www.postimage.org/