Q&A - PSLE Math

[tianzhu]

Suz855:

Need help with following speed qns


Q1) A car started travelling from Town A to Town B at 9a.m. At the same time, the lorry started travelling from Town B to Town A. The car had a speed of 20km/h faster than the lorry. The car passed the lorry 45km away from the midpoint. Given that the car reached Town B at 3p.m., what time would the lorry reached Town A? :?

Hi

Is this question from the past years papers?

Hope this helps.

Best wishes

http://farm9.staticflickr.com/8120/8679216577_5c3090f398_z.jpg\">

[tianzhu]

YumYum:

Tianzhu: do you have the working solution for the \"if\" series Qns? Stuck for Qn 2 and 4...and pie-seh if need to ask for other Qns ...thanks!

Hi

Please check your PM.

I've sent the solution for Q4 to you.

Best wishes.

[Suz855]

I copy these questions word for word, they are from an assessment book so pls do not be too bother, thks everyone for the help.


Q1- The car reached Town B at 3 pm or 5 pm ?
If the car reached at 3 pm, then the speeds for car and lorry are not realistic –> 30 km/h for car and 10 km/h for lorry.

Q2 - is the question complete ? any info left out - eg, at what time did Mr T and Mr R pass each other ? or Mr R is also travelling in the same direction ie from X to Y?

cheers.[/quote]

[wahwah]

Hi all,

Need help with the following question. Many thanks in advance.

Alex gave 40% of his angelfish to Peter. After that 15 of Alex’s angelfish died. He then gave 1/3 of the remaining angelfish to Peter. As a result, the ratio of Alex’s angelfish to Peter’s angelfish became 4:7. How many angelfish had Alex at first?

[tianzhu]

wahwah:

Hi all,

Need help with the following question. Many thanks in advance.

Alex gave 40% of his angelfish to Peter. After that 15 of Alex's angelfish died. He then gave 1/3 of the remaining angelfish to Peter. As a result, the ratio of Alex's angelfish to Peter's angelfish became 4:7. How many angelfish had Alex at first?

Hi

Good Morning.

This question is crafted in such a way that it is pretty neat to use MD.

Due to time constraints, I’ll be giving some pointers.

Draw a bar; divide into 4 units to show Peter (40%), and remaining 6 units.

Subdivide 15 into 3 smaller boxes of 5 each, remainder of 3 groups of (2 units - 5) ----- 1/3 given to Peter and 2/3 to Alex

And, in the end, we have,

Peter -------- 4 units + 2 units – 5 -------- 6 units – 5
Alex --------- 4 units – 10

As a result, the ratio of Alex's angelfish to Peter's angelfish became 4:7.

4 units – 10: 6 units – 5 ------ 4:7

28units – 70 -----24units – 20

1 unit ------ 12.5

Number of angelfish@first -------125

Best wishes

[wahwah]

Hi tianzhu,

Thanks a lot for the solution.

[CloudeeDaz]

tianzhu:

Good Morning.

This question is crafted in such a way that it is pretty neat to use MD.

Number of angelfish@first -------125

Best wishes

thank you ,tianzhu!
You made it seemed so simple!

......and to think that i acually spend some time last night trying (unsuccessfully )to work it out! :oops: :oops:

@wahwah thanks for the question!

[tianzhu]

wahwah:

Hi tianzhu,

Thanks a lot for the solution.

Hi

You're welcome.

Best wishes

[tianzhu]

CloudeeDaz:

thank you ,tianzhu!
You made it seemed so simple!

......and to think that i acually spend some time last night trying (unsuccessfully )to work it out! :oops: :oops:

@wahwah thanks for the question!

Hi

You're welcome.

KSP is a learning community.We share and learn together.

Best wishes

[enrichsg.040788ng]

I had a blog to help parents & students in solving world problem. The link is as below


http://excelprimaths.blogspot.sg

Thank you and wishing your kid excel in school.