Q&A - PSLE Math

Academic support for Primary 6 and PSLE
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fxchow
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Post by fxchow » Sat Aug 08, 2009 10:59 am

Hi,

Can someone help to solve this question. TIA. :)

James had some fishes in a tank. 15 were goldfish and the rest were guppies and angelfish.
The ratio of the number of goldfish to the number of guppies was 3:2 and the ratio of the number of guppies to the number of angelfish was 1:5. If James added 24 fish into the tank, the number of guppies would increase by 50%, and the angelfish would increase by 40%.
How many goldfish were added?

P/S: My girl told me that the question got mistake, please see if you can solve it. Question from school with no answer provided.

Dharma
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Post by Dharma » Sat Aug 08, 2009 12:56 pm

fxchow wrote:Hi,

P/S: My girl told me that the question got mistake, please see if you can solve it. Question from school with no answer provided.
You girl is right.
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Tang
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Post by Tang » Sat Aug 08, 2009 7:01 pm

Dharma wrote:
tianzhu wrote:Hi, hope this helps.
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This is small add on to Tianzhu's brilliant illustration.


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3 u = 2 p

1 p = 1 u + 1
2 p = 2 u + 2

3 u = 2 u + 2


1 u = 2; 1 p = 3

fxchow
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Post by fxchow » Sat Aug 08, 2009 9:09 pm

Dharma wrote:
fxchow wrote:Hi,

P/S: My girl told me that the question got mistake, please see if you can solve it. Question from school with no answer provided.
You girl is right.
Image
Hi Dharma,

Thanks for your reply. Have a nice weekend. :D

enoawng
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Post by enoawng » Mon Aug 10, 2009 12:02 pm

can anyone help?

John was n years old when his mother was 36 years old. Today, his mother is 3 times as old as John.
a) Express John’s age now in terms of n
b) What is John’s age now if n=8?


Dharma
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Post by Dharma » Mon Aug 10, 2009 7:34 pm

enoawng wrote:can anyone help?

John was n years old when his mother was 36 years old. Today, his mother is 3 times as old as John.
a) Express John’s age now in terms of n
b) What is John’s age now if n=8?
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David Koriadi
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Post by David Koriadi » Mon Aug 10, 2009 8:26 pm

Sandy bought some apples and oranges. The number of apples was 1 ¼ times the number of oranges. After she packed the apples into boxes of 10 and oranges into boxes of 6, she found that she had 2 more boxes of oranges than apples. How many apples did she buy at first?

Priskhipo
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Post by Priskhipo » Mon Aug 10, 2009 9:24 pm

David Koriadi wrote:Sandy bought some apples and oranges. The number of apples was 1 ¼ times the number of oranges. After she packed the apples into boxes of 10 and oranges into boxes of 6, she found that she had 2 more boxes of oranges than apples. How many apples did she buy at first?

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3greatkids
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Post by 3greatkids » Mon Aug 10, 2009 11:14 pm

enoawng wrote:can anyone help?

John was n years old when his mother was 36 years old. Today, his mother is 3 times as old as John.
a) Express John’s age now in terms of n
b) What is John’s age now if n=8?
a) John's age now is (36-n)/2.
The theory is that the difference between mother's age and john's age never change, therefore, the difference in their age is always 36-n.
In order for the mother to be 3 times as old as John, when u draw the model, John will be 1 unit whereas mum is 3 units. their age difference(36-n) will then take up 2 units and john's age would be 1 unit. so in order to find 1 unit, you will take (36-n)/2

b) thus john's age now is (36-8)/2 which is 14

James Ang
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easy and common question

Post by James Ang » Mon Aug 10, 2009 11:26 pm

Question asked:
Mary and Peter attended a party. Peter met with 4 times as many boy as girls while Mary met with 5 times as many boys as girls. How many boys and girls were at the party?

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