Q&A - PSLE Math

[Dharma]

fxchow:

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.
http://www.postimage.org/

[Tang]

Dharma:

tianzhu:

Hi, hope this helps.

http://farm4.static.flickr.com/3447/3790867316_9c928f2e6d_o.jpg\">

This is small add on to Tianzhu's brilliant illustration.


http://www.postimage.org/

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]

Dharma:

fxchow:

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.
http://www.postimage.org/

Hi Dharma,

Thanks for your reply. Have a nice weekend.

[enoawng]

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]

enoawng:

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?

http://www.postimage.org/

[David Koriadi]

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]

David Koriadi:

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?

http://www.postimage.org/

[3greatkids]

enoawng:

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]

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?

[3greatkids]

James Ang:

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?

not able to attach image....

anyway, let me try n explain:

first draw a model from peter's perspective. thus 1u= girls and 4u=boys.

When we put peter back in and mary out from the equation - cut a section out from girls and indicate 1. the cutout is used to represent mary. cut an equal part from each of the 4u and add 1 more to indicate peter.

The remainder from the cutout part from the girls is used to represent 1u from mary's perspective. after cutting the previous model, we have 4 equal units and 5 cutouts(including peter) thus we can deduce:

1u=5
5u=25(boys)

girls=1u + Mary = 5+1 = 6
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