Q&A - PSLE Math

Academic support for Primary 6 and PSLE
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BlueBelt
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Post by small » Tue Aug 25, 2009 10:35 pm

tianzhu wrote:Hi

I think the answer is 9am.

Time taken by Mr Ong --> 12 hours
Time taken by Mr Lee --> 15 hrs

Where is this Q from?It can be considered as a higher order speed Q where proportion method may be more appropriate.

Best Wishes
Hi Tianzhu, :celebrate:

Can you show me the working? Thanks in advance.


I am still trying to figure out Vanilla's working.... :oops:

heutistmeintag
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Post by heutistmeintag » Wed Aug 26, 2009 2:33 am

Hi all, need urgent help on these 3 questions. TIA!

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small
BlueBelt
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Post by small » Wed Aug 26, 2009 6:25 am

small wrote:Hi Tianzhu, :celebrate:

Can you show me the working? Thanks in advance.


I am still trying to figure out Vanilla's working.... :oops:
Hi Tianzhu and Vanilla Cake, I managed to figure out the working, thanks for oyur help. :celebrate:

tianzhu
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Post by tianzhu » Wed Aug 26, 2009 10:24 am

Hi moderator

Please help to delete this post.

Thank you
Last edited by tianzhu on Wed Sep 02, 2009 2:31 pm, edited 2 times in total.

tianzhu
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Post by tianzhu » Wed Aug 26, 2009 10:29 am

small wrote: Hi Tianzhu and Vanilla Cake, I managed to figure out the working, thanks for oyur help. :celebrate:
Hi
This is quite an interesting question.Great, you've got it.

Enjoy your journey.

Best Wishes


Dharma
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Post by Dharma » Wed Aug 26, 2009 10:39 am

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Priskhipo
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Post by Priskhipo » Wed Aug 26, 2009 8:50 pm

heutistmeintag wrote:Hi all, need urgent help on these 3 questions. TIA!

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Hi heutistmeintag,

The solutions are as follow:


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Tang
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Post by Tang » Wed Aug 26, 2009 9:21 pm

Vanilla Cake wrote:
small wrote:Hi all,
Thanks for your time. My DD's answer is 5pm.
Question:
Mr Lee left Town M for Town N at a speed of 80km/h. Mr Ong also left Town M for town N one hour later at a speed of 100km/h. Mr Ong reached Town Q, which was was in the middle of Town M and N, 30 mins earlier than Mr Lee. If Mr Ong reached Town N at 10pm, what time did Mr Lee leave Town M?
Hi small,
Is this qn from your DD's P6 Prelim exam? The answer is 9 am.

Difference in distance between Mr Lee and Mr Ong = 1.5 x 80 = 120 km.
Required time for Mr Ong to catch up with Mr Lee = 120 / (100-80) = 6 h
Distance from Town M to Town Q = 6 x 100 = 600 km
Total distance between Town M and Town N = 600 x 2 = 1200 km
Time taken for Mr Ong to travel from Town M to Town N=1200/100 = 12 h

Since Mr Lee started 1 hour earlier, that meant he took 13 h to travel.
Use timeline:

9 am.............12 pm...................10 pm
......................3 h......................10 h
Unlined statement may not be quite correct as Time difference of 1.5 h is not Required time for Mr Ong to catch up with Mr Lee.

Speed of Mr Lee (SL) : Speed of Mr Ong (SO) = 80 : 100 = 4 : 5

For the same distance, SL : SO = TO : TL = 4 : 5

Difference in time, 1 u = 2 x (1 + 0.5) = 3 h

TO : 4 u = 4 x 3 = 12 h

Timeline

9am ..... 1 h ..........10 am..... 2 h ..........12 noon..... 10 h ....... 10 pm
Starting time of Mr Lee = 9 a.m.

small
BlueBelt
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Post by small » Wed Aug 26, 2009 11:03 pm

Hi Dharma and Tang,

thanks for your help.

:celebrate:

faith2u
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Just 1 maths question

Post by faith2u » Fri Aug 28, 2009 2:08 pm

A group of tourists visited an art exhibition. The admission tickets were $3 for adult and $2 for a child. If the ratio of the number of tourists to the number of dollar collected for admission was 8:21, what fraction of the tourists were children?

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