PSLE Maths 2012

[24hr_mum]

wargame123:

question 29 answer is 28. right

from what my son says the method is as follows
110 minus 1 as the last man is an extra out of the group
then use 109 divided by 4 which gives u 27 r1 as in a group there can be 3 women and 1 men
the remainder of 1 means that in one of the group they have 4 women
then add 1 to 27 as there is still a man at the back
and my son also said that those ppl who put 44 has double counted the man
making it: m w w w m m w w w m m
thus it will have no women in betwwen some of the men

My dd ans also 28

[Clairifina]

The last question was quite tough… Does anybody know how to do it? Even the top math student in my class was struggling.

[wargame123]

the radius of the circle is 50 divided by 2 having 25

use pi r square and get 1962.5
then find the area of the imaginary small square which is 50 times 50 having 2500
use 2500 minus 1962.5 and get 537.5
and times 38 as there are 38 of 537.5 as ther are 38 imaginary squares anf 38 circles which give u 20525 thats for part a
for b its 38 circles minus 4 circles at the corner givibg u 34
use 34 divided 2 giclving u 17 thus 17 circles surrounding 1 length and breathof the rectangle
the circle had a diameter of 50 thus use 50 times 17 which give u 850
as ther are 2 lenght and 2 beath use 850 times 2 giving u 1700
i hope my answer is correct

[Clairifina]

Tnx. How about the cupboard question? Not too sure about my answer.

[AlphaY]

2.64m for b)

[wargame123]

cardboard answers

a) 16
b) either 2.46 or 2.64. cannot remember the ans

[ximinful]

wargame123:

the radius of the circle is 50 divided by 2 having 25

use pi r square and get 1962.5
then find the area of the imaginary small square which is 50 times 50 having 2500
use 2500 minus 1962.5 and get 537.5
and times 38 as there are 38 of 537.5 as ther are 38 imaginary squares anf 38 circles which give u 20525 thats for part a
for b its 38 circles minus 4 circles at the corner givibg u 34
use 34 divided 2 giclving u 17 thus 17 circles surrounding 1 length and breathof the rectangle
the circle had a diameter of 50 thus use 50 times 17 which give u 850
as ther are 2 lenght and 2 beath use 850 times 2 giving u 1700
i hope my answer is correct

Part a is 20425. Check ur calculation

[kaparent]

wargame123:

the radius of the circle is 50 divided by 2 having 25

use pi r square and get 1962.5
then find the area of the imaginary small square which is 50 times 50 having 2500
use 2500 minus 1962.5 and get 537.5
and times 38 as there are 38 of 537.5 as ther are 38 imaginary squares anf 38 circles which give u 20525 thats for part a
for b its 38 circles minus 4 circles at the corner givibg u 34
use 34 divided 2 giclving u 17 thus 17 circles surrounding 1 length and breathof the rectangle
the circle had a diameter of 50 thus use 50 times 17 which give u 850
as ther are 2 lenght and 2 beath use 850 times 2 giving u 1700
i hope my answer is correct

38 x 537.5 = 20425 but your answer is 20525?

[kaparent]

kaparent:

wargame123:

the radius of the circle is 50 divided by 2 having 25

use pi r square and get 1962.5
then find the area of the imaginary small square which is 50 times 50 having 2500
use 2500 minus 1962.5 and get 537.5
and times 38 as there are 38 of 537.5 as ther are 38 imaginary squares anf 38 circles which give u 20525 thats for part a
for b its 38 circles minus 4 circles at the corner givibg u 34
use 34 divided 2 giclving u 17 thus 17 circles surrounding 1 length and breathof the rectangle
the circle had a diameter of 50 thus use 50 times 17 which give u 850
as ther are 2 lenght and 2 beath use 850 times 2 giving u 1700
i hope my answer is correct

38 x 537.5 = 20425 but your answer is 20525?

It should be 20425 and if your answer for (a) is 20425 and b is 1700 your are spot on! My kid answer is also the same. He is his school top student.

[CrimsonSunset]

So disappointed...


This year's English and Math papers have all been very easy...