Q&A - PSLE Math

Academic support for Primary 6 and PSLE
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bangs
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Re: Q&A - PSLE Math

Post by bangs » Wed Feb 26, 2014 8:39 pm

Hi,

Help. please!
-----------
Ahmad and Halim together took 5 days to paint their house. If Ahmad and Halim work together for 2 days, followed by Ahmad working alone for 8 days, Halim will take 1 more day to complete the remaining work. How long will Ahmad take to paint the house all by himself?

Ans given: 17.5 days

-----------
Thanks in advance!

Oldschool
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Re: Q&A - PSLE Math

Post by Oldschool » Wed Feb 26, 2014 8:41 pm

acehkr3009 wrote:
Oldschool wrote:
acehkr3009 wrote:Hi all,

Will need help on finding the area of the unshaded triangle.

Thanks.

Image
Hi,

Can you find the area of triangle from here?

Image

Regards
Hi,

Thanks for the reply.

The triangles are not stated as right angle triangle.
Is it possible to have isosceles triangles inside this quadrant that may not be right angle?
If so, then not too sure how to find area of the triangles....please advise...thks

Hi,

Yes, it is possible to have iso. triangle inside the quadrant that is not a right angle triangle.

So, you have a valid point here. If the iso. triangle is not a rt. angle triangle (since it is stated that is not drawn to scale) them there would be infinite answers.

Regards

ksdad28
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Re: Q&A - PSLE Math

Post by ksdad28 » Wed Feb 26, 2014 9:25 pm

tianzhu wrote:
ksdad28 wrote:The ratio of the number of fishes to the number of frogs in a pond is 3:5. After 6 frogs left the pond, there were 6/7 as many fishes as frogs. How many fishes and frogs were there altogether in the pond at first?

TIA for helping.
Hi ksdad28

Good Morning

Hope this helps.

Best wishes

Image
Thanks. Ratio is one of my worst topics.

speedmaths.com
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Re: Q&A - PSLE Math

Post by speedmaths.com » Wed Feb 26, 2014 9:44 pm

bangs wrote:Hi,

Help. please!
-----------
Ahmad and Halim together took 5 days to paint their house. If Ahmad and Halim work together for 2 days, followed by Ahmad working alone for 8 days, Halim will take 1 more day to complete the remaining work. How long will Ahmad take to paint the house all by himself?

Ans given: 17.5 days

-----------
Thanks in advance!
Hi bangs,

Please see the page below.

http://www.kiasuparents.com/kiasu/forum ... start=3830

Please let us know if you still need help.

Cheers



speedmaths.com
.

sptamila
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Re: Q&A - PSLE Math

Post by sptamila » Thu Feb 27, 2014 11:49 am

bangs wrote:Hi,

Help. please!
-----------
Ahmad and Halim together took 5 days to paint their house. If Ahmad and Halim work together for 2 days, followed by Ahmad working alone for 8 days, Halim will take 1 more day to complete the remaining work. How long will Ahmad take to paint the house all by himself?

Ans given: 17.5 days

-----------
Thanks in advance!
1A +1H ---------- 1/5 of the house painted in 1 day
2day of (Ahamed + Halim) 2A+ 2H ----- 2/5 of the works done.
Remaining paint work 5/5 – 2/5 = 3/5
3 / 5 works -------- A8 days + H 1 day
1day of A + 1 day of H = 1/5 of the house painted --------(1)
8day of A + 1 day of H = 3/5 of the house painted --------(2)
(2) –(1) = 7 day of A = 2/5 of the house paint work
5/5 of the house paint work by A = 5/2 X 7 = 17.5 days

Cheers
SPt


sptamila
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Re: Q&A - PSLE Math

Post by sptamila » Thu Feb 27, 2014 12:48 pm

Oldschool wrote:
acehkr3009 wrote:Hi all,

Will need help on finding the area of the unshaded triangle.

Thanks.

Image
Hi,

Can you find the area of triangle from here?

Image

Regards
Here you go
Hi,
Area of the 2 Quadrant = π ×r² / 2
22/ 7 x 20 x 20 / 2 = 628. 57cm² (rounded off)

2 Area of Isosceles triangles = 1 Square
Quadrant Radius = Square diagonal of a Squre (20 cm)
Area of the Square using Diagonal = d²/2
20 x 20 / 2 = 200 cm²

Shaded parts = 628.57 – 200 = 428.57cm²

Cheers
Spt
Image

bangs
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Re: Q&A - PSLE Math

Post by bangs » Thu Feb 27, 2014 3:14 pm

sptamila wrote:
bangs wrote:Hi,

Help. please!
-----------
Ahmad and Halim together took 5 days to paint their house. If Ahmad and Halim work together for 2 days, followed by Ahmad working alone for 8 days, Halim will take 1 more day to complete the remaining work. How long will Ahmad take to paint the house all by himself?

Ans given: 17.5 days

-----------
Thanks in advance!
1A +1H ---------- 1/5 of the house painted in 1 day
2day of (Ahamed + Halim) 2A+ 2H ----- 2/5 of the works done.
Remaining paint work 5/5 – 2/5 = 3/5
3 / 5 works -------- A8 days + H 1 day
1day of A + 1 day of H = 1/5 of the house painted --------(1)
8day of A + 1 day of H = 3/5 of the house painted --------(2)
(2) –(1) = 7 day of A = 2/5 of the house paint work
5/5 of the house paint work by A = 5/2 X 7 = 17.5 days

Cheers
SPt
Thanks for your help in solving and to speedmaths for directing me to a previous post on this same question. Much appreciated! :smile:

marstolive
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Re: Q&A - PSLE Math

Post by marstolive » Thu Feb 27, 2014 4:01 pm

:?: A farmer had 160 more chickens than ducks.
After selling 3/4 of the ducks and 50% of the chickens, 230 chickens and ducks were left.

a. how many duck were left
b. what is the ratio of the number of chickens left to the number of ducks left? express your answer in its simplest form.

:thankyou:

sptamila
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Re: Q&A - PSLE Math

Post by sptamila » Thu Feb 27, 2014 5:57 pm

marstolive wrote::?: A farmer had 160 more chickens than ducks.
After selling 3/4 of the ducks and 50% of the chickens, 230 chickens and ducks were left.

a. how many duck were left
b. what is the ratio of the number of chickens left to the number of ducks left? express your answer in its simplest form.

:thankyou:
Hi,
Image

Cheers!!!
Spt

SOS mum
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Re: Q&A - PSLE Math

Post by SOS mum » Thu Feb 27, 2014 8:02 pm

Hi, ps help. TIA

Mr Chen receives a fixed salary every month. He sets aside $500 for his son's monthly allowance, $1500 for family expenditure and saves the rest. When he increases his son's allowance by $64, his savings decreases by 8%. Find his monthly salary.

In an examination, Mary scored an average percentage of 80% for 4 subjects. She got 10 more marks in Chinese than in English. She scored 5 marks more in English than her maths and her science marks were 3/4 that of what she scored for English. How many marks did she score for each subject?

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