Q&A - P5 Math

[tianzhu]

newuser:

I am lost in explaining to this DS.
Anyone can help to draw MD for us to visualize?

Hi

Hope this helps.

Best wishes

http://farm9.staticflickr.com/8521/8597362780_3351ff8915_z.jpg\">

[Jamesbond]

quekcc:

Jamesbond:

http://i50.tinypic.com/fcv5hc.jpg\">

Help needed.

Find area of triangle ACD, and take away area of triangles AEO, EDF and FOC.

Note that AE=4, ED=16, DF=3, FC=9.

Area of ACD = 120
Area of AEO = 12 (height is 6)
Area of EDF = 24
Area of FOC = 45 (height is 10)

Answer = 39

:thankyou: queckcc

[Jamesbond]

http://i46.tinypic.com/161ant.jpg\">

Pl help....

[carol73]

pls help to provide ans to the below, I want to confirm if my solution is correct


There were 147 glasses for sale. 10/21 of them were blue and the rest were yellow. When some blue glasses were sold, the number of blue glassess left was 4/15 of the total number of glasses left, how many blue glasses were sold.


there were 889 pupils in a school. 1/3 o fthe girls and 1/2 of the boys were in the upper primary classess. there were equal number of boys and girls in the lower primary classes. find the number of girls and the number of boys in the school

[ChewingPencilLine]

carol73:

pls help to provide ans to the below, I want to confirm if my solution is correct


There were 147 glasses for sale. 10/21 of them were blue and the rest were yellow. When some blue glasses were sold, the number of blue glassess left was 4/15 of the total number of glasses left, how many blue glasses were sold.


there were 889 pupils in a school. 1/3 of the girls and 1/2 of the boys were in the upper primary classes. there were equal number of boys and girls in the lower primary classes. find the number of girls and the number of boys in the school

Q1: 42
Q2: 381 girls, 508 boys

[tianzhu]

Jamesbond:

http://i46.tinypic.com/161ant.jpg\">

Pl help....

Hi

Good Morning.

Area of triangle ABC ------ 315*2 -------630

Divide the square in triangle XYZ into 4 smaller triangles; you will see that triangle XYZ has 9 such small triangles altogether.

Hence the area of square in triangle XYZ ------4/9*630 ------ 280

Best wishes

[Jamesbond]

tianzhu:

Jamesbond:

http://i46.tinypic.com/161ant.jpg\">

Pl help....

Hi

Good Morning.

Area of triangle ABC ------ 315*2 -------630

Divide the square in triangle XYZ into 4 smaller triangles; you will see that triangle XYZ has 9 such small triangles altogether.

Hence the area of square in triangle XYZ ------4/9*630 ------ 280

Best wishes

Good morning Tianzhu....I got it. Thanks for ur help.

[Jamesbond]

http://i50.tinypic.com/35kivcm.jpg\">

Help needed.

[tianzhu]

Jamesbond:

http://i50.tinypic.com/35kivcm.jpg\">

Help needed.

Hi

The logic behind this question is similar to your earlier one.

Best wishes

[Jamesbond]

tianzhu:

Jamesbond:

http://i50.tinypic.com/35kivcm.jpg\">

Help needed.

Hi

The logic behind this question is similar to your earlier one.

Best wishes

Actually I worked out this sum. For (a) I had a doubt of including the smaller sq W in calculating the area of sq MQPN. For (b) my ans is 200. Ans in ans sheet is 225. Can u let me know the correct ans.