Thanks small. It’s not that i do not know that a triangle is 1/2 base x height. It’s just that at first i cannot see that the unshaded part is actually made up of half the rectangle. But now i get it already. Thanks. Thanks to all who helped me.

small:

Please invert the diagram and take a look, it will be more clear.
The base of two triangles is 45 cm and the height is 22cm, thus their area:
1/2 x 45 x 22 which will be same as half of rectangle (area of rectangle = 45 x 22 )

i cannot see it

Dharma:

elkniwt:

[quote=\"tianzhu\"]Thank you for your help.


http://farm3.static.flickr.com/2547/3984945203_a6bc525a6c_o.jpg\">

Hi,

Is the answer 19:14?

If yes, this is how I got it, but I'm not sure if you can do the working this way in primary sch.

Unshaded = Area of triangle PRV + Area of triangle VSQ - overlap
= 1/2 x QR x PV + 1/2 x QR x VQ - 75
= 1/2 x 45 x 22 - 75
= 420
Shaded = Area of rect - unshaded
= 45 x 22 - 420
= 570
Hence ratio of shaded to unshaded is 570:420 = 19:14

The unshaded area = Area of 1/2 rect - 75 = 495 - 75 = 420
Shaded area : Unshaded area = (495 + 75) : 420 = 570 : 420 = 19:14[/quote] how the unshaded area = Area of 1/2 rect
i cannot see it

Thanks a lot. I get it now.

MdmKS:

k1ndan:

http://i300.photobucket.com/albums/nn19/k1ndan/Maths3.jpg\">

b) 42 - 22 = 20 cm
22 - 20 = 2 cm
height of a flower pot = 20 - 2 = 18 cm

why 22 - 20? Oh dear.

Can anyone tell me how the breakdown of thetopic tested in PSLE? i am feeling stressed. Thanks.

Thanks everyone!

James Ang:

i calculated the remainder to be of this sequence,

1000, 666and2/3, 500, 400...
=> 2000/2, 2000/3, 2000/4, 2000/5....

the final remainder is 2000/2000 = 1 left.

Sorry James, I don't quite understand. I only know up to the 1000 part. :oops:

My boy got this problem. Can someone help me to solve this?


Monkey King had 2000 pears. He gave all the pears to some monkeys. On the first day, the monkeys ate half of the total number of pears. On the second day, they ate 1/3 of the remaining pears. On the third day, they ate 1/4 of the rest of the pears. They went on to eat the pears as 1/5,1/6,1/7,…,1/2000 of the remainder of every previous day’s pears. Find the number of pears left at the end.

Thanks. By the way, please explain clearly because i m a not so smart mum.

Thanks Dharma, i am still trying to figure it out. Really thanks so much. Sometimes i really wonder how can children 12 year old brain think so much.