Q&A - PSLE Math

[Drdj]

[Moderator's note: Topics merged.]


Hi,
Can you help me to solve this question? (preferably non-algebra, if possible).
The answer given is 1/3.
Thanks in advance.

http://www.postimage.org/image.php?v=aVLOAnr

[tianzhu]

Hi

Hope this helps.
http://farm3.static.flickr.com/2454/3575392074_9a6a4cfa56_o.jpg\">

[faith2u]

[Moderator's note: Topics merged.]


Q1). Alan, Bill and Chris had 98 pencils altogether at first. After Alan gave away 5 pencils, Bill doubled his pencils and Chris received 3 more pencils, the ratio of pencils Alan had to the pencils Bill has to the pencil Chris had become 1:4:5. How many pencils did each of them have at first?

Q2). Town S and P are 375km apart. A van started from Town S towards Town P at a uniform speed of 60km/h while a motorcyclist started from Town P to Town S at a uniform speed of 90km/h. Both vehicles started their journey at 0600h.
(a). At what time did they pass each other?
(b). How far away was the van from Town P when it passed the motorcycle?

Thanks in advance.

[David Koriadi]

Q1

At first, Alan, Bill and Chris had 17, 24 and 57 pencils respectively.

Q2
(a) They passed each other at 0830 h
(b) The van was 225 km from Town P when it passed the motorcycle.

[Drdj]

Hi,


thanks a lot !! for the colorful background picture too !!

tianzhu:

Hi
Hope this helps.
http://farm3.static.flickr.com/2454/3575392074_9a6a4cfa56_o.jpg\">

[tianzhu]

Hi

Hope this helps.

http://farm4.static.flickr.com/3584/3574669589_d380e6cdc2_o.jpg\">

[tianzhu]

Q2). Town S and P are 375km apart. A van started from Town S towards Town P at a uniform speed of 60km/h while a motorcyclist started from Town P to Town S at a uniform speed of 90km/h. Both vehicles started their journey at 0600h.

(a). At what time did they pass each other?
(b). How far away was the van from Town P when it passed the motorcycle?

Hi
Just a quick one for Q2

For them to meet , the sum of distances travelled by the van and motorcycle is equal tp 375km

a) The time taken is 375/150 --> 2.5h
Therefore they met at 0830hrs.

b) For 2.5h, the van travelled 150km (2.5*60)
Therefore its distance from Town P --> 225km

[tianzhu]

Drdj:

Hi,

thanks a lot !! for the colorful background picture too !!

Hi
Glad you like it.I've also answered the same question in another forum.It's from CHIJ St Nicholas P6 SA1 2008.

We need ChiefKiasu's help to move this post to the relevant section.

Best wishes

[Denise]

John had $228 and Kevin had $204. Kevin spent thrice as much as John. If John had thrice as much money as Kevin after spending, how much did Kevin spend?


How do you draw the model for this question

[kiasiparent]

Denise:

John had $228 and Kevin had $204. Kevin spent thrice as much as John. If John had thrice as much money as Kevin after spending, how much did Kevin spend?


How do you draw the model for this question

Model method is very tedious for this question. I recommend drawing table instead.

Assume John spent 1 units and Kevin spent 3 units

Then John have 3 parts left and Kevin has 1 part left.


name| units | parts | total
John | 1 | 3 | 228
Kevin|3 | 1 | 204
K x3 |9 | 3 | 612

Therefore 8 units = 612 - 228 = 384
1 unit = 384 / 8 = 48
3 units = $144