Q&A - PSLE Math

[Robertpattinsonidle]

zeemimi:

jewelbox:

Hi, how do I solve this qn? Thanks. http://i47.tinypic.com/2j1si1k.jpg\">

(a) ¼ x 2 π 3 + ¼ x 2 π 2 + 3/4x2 π 1 = 4 π

(b)

(A) Area of big quad = ¼ π3x3 = 9/4 π
(B) Area of white space under medium quad = 2x2 – ¼ π2x2 = 4 – π
(C) Area of white space in rect under smallest quad = 2x1 – ¼ π1x1= 2 – ¼ π
(D) Area of semi circle = ½ π 1x1= ½ π
Area of shaded region = (A) – (B) – (C) + (D) = 6.57 cm2

can u explain the last step? i cant understand. thank you

[tianzhu]

Robertpattinsonidle:

can u explain the last step? i cant understand. thank you

Hi

If you prefer to deal with familiar shapes, here’s an alternate way.

At this moment, just days before PSLE, students should be well versed in dealing with familiar shapes.

I’ll leave you to do the calculations.

All the best to your PSLE.

Best wishes

http://farm9.staticflickr.com/8308/7981184268_7541c7b434_z.jpg\">

[Chenonceau]

http://i46.tinypic.com/2jez6fo.jpg\">


Can someone help? Thanks!

[maychang]

Hi, my dd had gotten the answer is 216 members in March, but the answer key is 432 membe

Can anyone help to confirm if the answer key is wrong? My dd said her answer is correct.
Thanks.

The numbers of members in swimming club increased by 25% in February compared to January.
However, the number of members in March dropped by 10% compared to February. If the difference in the number of members between January and February was 48, how many members were there in March?

[maychang]

Hi, my dd had gotten the answer is 216 members in March, but the answer key is 432 membe

Can anyone help to confirm if the answer key is wrong? My dd said her answer is correct.
Thanks.

The numbers of members in swimming club increased by 25% in February compared to January.
However, the number of members in March dropped by 10% compared to February. If the difference in the number of members between January and February was 48, how many members were there in March?

[ximinful]

maychang:

Hi, my dd had gotten the answer is 216 members in March, but the answer key is 432 membe

Can anyone help to confirm if the answer key is wrong? My dd said her answer is correct.
Thanks.

The numbers of members in swimming club increased by 25% in February compared to January.
However, the number of members in March dropped by 10% compared to February. If the difference in the number of members between January and February was 48, how many members were there in March?

My Ans is also 216

[dicoyote]

Hi,


Need help on this question, thanks

A fruit seller had some oranges, pears, and durians. After selling some of them, there were 6 pears for every 5 oranges left and 7 oranges for every 3 durians left. He sold 168 oranges. He had 456 pears and oranges left. The number of pears sold was the same as the number of durians sold.
a) How many oranges had he at first?
b) If the number of pears was twice the number of durians at first, what was the total number of pears and durians sold?

[small]

dicoyote:

Hi,


Need help on this question, thanks

A fruit seller had some oranges, pears, and durians. After selling some of them, there were 6 pears for every 5 oranges left and 7 oranges for every 3 durians left. He sold 168 oranges. He had 456 pears and oranges left. The number of pears sold was the same as the number of durians sold.
a) How many oranges had he at first?
b) If the number of pears was twice the number of durians at first, what was the total number of pears and durians sold?

Hi dicoyote,

This question was discussed in the past as there was a problem with the number, change 456 to 462 and you should be able to solve the question.

Please refer to this, http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=6373&postdays=0&postorder=asc&start=2480

[dicoyote]

Hi small,


Thanks for the reply, glad that you pointed out the link on the possible mistake within the question

small:

dicoyote:

Hi,

Need help on this question, thanks

A fruit seller had some oranges, pears, and durians. After selling some of them, there were 6 pears for every 5 oranges left and 7 oranges for every 3 durians left. He sold 168 oranges. He had 456 pears and oranges left. The number of pears sold was the same as the number of durians sold.
a) How many oranges had he at first?
b) If the number of pears was twice the number of durians at first, what was the total number of pears and durians sold?

Hi dicoyote,

This question was discussed in the past as there was a problem with the number, change 456 to 462 and you should be able to solve the question.

Please refer to this, http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=6373&postdays=0&postorder=asc&start=2480

[MathIzzzFun]

Chenonceau:

http://i46.tinypic.com/2jez6fo.jpg\">


Can someone help? Thanks!

Hi
may I know the source of the question ? I think this is beyond P6 syllabus.

I did a quick calculation using trigo and pythagoras, Area A = 1.72 cm² (to 2 decimal places, and with pi=3.14).

cheers.