Q&A - PSLE Math

[ck123]

Thanks All


Ai yo , finally managed to see that the radius is the same as AD. Paiseh.

[MathIzzzFun]

Daddy:

Thanks MathIzzzFun

Q2.

http://i56.tinypic.com/2mgwklt.jpg\">

cheers.[/quote]

How did you get 3: 2 ratio of Mary to John?
How about John bought 40% of the totalnumber of clips and ribbons?

I am not quiet understand. Sorry for that.[/quote]

Hi

John bought 40% of total number of ribbons and clips, so Mary bought 60% of total number of ribbons and clips.
Ratio of total number bought by Mary to John = 60 : 40 = 3:2

cheers.

[tianzhu]

Heeheehaha:

Pls help to solve the following :-

Alan had some apples and oranges. There were 75 more apples than oranges. After he sold 4/5 of the apple & 3/4 of the oranges, he had 285 fruits left. How many apples did he have at 1st？

Hi

You may use MD or UM to do it.

Apples ----- 20 units + 75
Apples sold ------ 16 units + 60
Apples left ------ 4 units + 15

Oranges ----- 20units
Oranges sold ------ 15 units
Oranges left ------ 5 units

5 units + 4 units + 15 ----- 285
1 unit ------ 30

Number of apples ------ (20*30) + 75 --------675

Best wishes

[Heeheehaha]

tianzhu:

Heeheehaha:

Pls help to solve the following :-

Alan had some apples and oranges. There were 75 more apples than oranges. After he sold 4/5 of the apple & 3/4 of the oranges, he had 285 fruits left. How many apples did he have at 1st？

Hi

You may use MD or UM to do it.

Apples ----- 20units + 75
Apples sold ------ 16 units + 60
Apples left ------ 4 units + 15

Oranges ----- 20units
Oranges sold ------ 15 units
Oranges left ------ 5 units

Hi Tian Zhu, should we add 75 in order to get the total quantity of apple?

Thanks for your fast response & help!

5 units + 4 units + 15 ----- 285
1 unit ------ 30

Number of apples ------ 20*30 --------600

Best wishes

[tianzhu]

Heeheehaha:

Hi Tian Zhu, should we add 75 in order to get the total quantity of apple?
Thanks for your fast response & help!

Hi

Yes we should add 75 to 600.

My mistake,I'll amend the solution..

Best wishes

[ozora]

tianzhu:

michyms:

tianzhu, can you explain how you assigned the units? I'm a little confused. Thanks.

Hi

That reply was to address ozora’s query.It lacked details.

A similar type of question was discussed in an earlier post.

Please follow this link.

http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=2920
page 293@Wed Apr 13, 2011 9:07 am

Best wishes

thanks tianzhu. may i know how do u manage to retrive the link on the following question. I remember asking the similiar question before but I was unable to search it.

[tianzhu]

Hi moderator


Please help to delete.

Best wishes

[Eddow]

http://i51.tinypic.com/x1n6zl.png\">

Answer given: (b) ~83.91 cm

Pls wait for Uncle tianzhu / MathIzzzFun to provide worked solutions.
Thks.[/quote]

Thanks Tianzhu for the solution. Maybe this might be easier, as I coundn't figure out the rotation myself... :?

Given the 135 degree, angle ODB = 45 degree.
If you draw a line joining OT, angle OTE = 45 degree (half of 90 degree of square) . This straight away give OT = DB.
And the rest of the calculation applies..

[andante]

Eddow:

http://i51.tinypic.com/x1n6zl.png\">

Answer given: (b) ~83.91 cm

Pls wait for Uncle tianzhu / MathIzzzFun to provide worked solutions.
Thks.

Thanks Tianzhu for the solution. Maybe this might be easier, as I coundn't figure out the rotation myself... :?

Given the 135 degree, angle ODB = 45 degree.
If you draw a line joining OT, angle OTE = 45 degree (half of 90 degree of square) . This straight away give OT = DB.
And the rest of the calculation applies..[/quote]

Hi,
I agree with you as the quadrilateral can be easily proved to be parallelogram, thus OT=DB.

[tianzhu]

Hi moderators


Please help to delete this post.

Best wishes