Q&A - PSLE Math
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starfish53:
this was discussed :Can anyone help me with the following question?
Q2) Mary bought some red marbles and gave half to Noel.
Noel bought some blue marbles and gave half to Mary.
Mary lost 16 red marbles and Noel lost 55 blue marbles.
The ratio of Mary's red marbles to blue marbles became 18 : 85 and
the ratio of Noel's red marbles to blue marbles became 7 : 20.
How many red marbles marbles did Mar buy?
Thanks in advance.
- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=9190
- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=9200
similar questions at:
- http://www.flickr.com/photos/mathizzzfun/6943541872/in/set-72157632928079102
- http://www.flickr.com/photos/mathizzzfun/8196644004/in/set-72157632037121311
cheers. -
starfish53:
Tina's money --> 4 units,Can anyone help me with the following question?
Q1) 3/5 of Bette's money is $324 more than 3/4 of Tina's money.
Bette has twice as much as Tina.
a) How much does Tina have?
b) How much does Bette have?
Thanks in advance.
3/4 of Tina's money --> 3 units
3/5 of Bette's money -->3 units + $324 = 3 x (1 unit + $108)
Bette's money (5/5) --> 5 x (1 unit + $108) = 5 units + $540
Bette has twice as much as Tina
so,
5 units + $540 = 8 units
1 unit --> $180
Tina's money --> $ 720
Bette's money --> $ 1440
cheers. -
Dear MathIzzzFun,
Thank you so much for your help!
Regards/ -
need help in the following question:
1) Tom’s present age is twice more than Sam’s age years ago. Today, Sam’s age is the same number of years ago. How old is Tom now if the sum of their present age is 30? -
ozora:
any missing info ?need help in the following question:
1) Tom's present age is twice more than Sam's age years ago. Today, Sam's age is the same number of years ago. How old is Tom now if the sum of their present age is 30?
If the sentence is \"Today, Sam's age is the same as Tom's age same number of years ago\", then
Now, Sam's age --> 12 years, Tom's age --> 18 years
6 years ago, Sam's age --> 6 years, Tom's age --> 12 years.
cheers. -
starfish53:
For this kind of question, I like to use simultaneous equations because you just need to draw the model according to the logical understanding of the facts. This is useful especially for those who are good in interpreting the facts into models.Can anyone help me with the following question?
Q1) 3/5 of Bette's money is $324 more than 3/4 of Tina's money.
Bette has twice as much as Tina.
a) How much does Tina have?
b) How much does Bette have?
Thanks in advance.
http://i42.tinypic.com/3169jeu.jpg\"> -
MathIzzzFun:
yes there is missing infor.thanks for the highlight. sam's age is tom's age the same number of years ago.
any missing info ?ozora:
need help in the following question:
1) Tom's present age is twice more than Sam's age years ago. Today, Sam's age is the same number of years ago. How old is Tom now if the sum of their present age is 30?
If the sentence is \"Today, Sam's age is the same as Tom's age same number of years ago\", then
Now, Sam's age --> 12 years, Tom's age --> 18 years
6 years ago, Sam's age --> 6 years, Tom's age --> 12 years.
cheers. -
ozora:
need help in the following question:
1) Tom's present age is twice more than Sam's age years ago. Today, Sam's age is Tom's age the same number of years ago. How old is Tom now if the sum of their present age is 30?
Using units/parts method:
Number of years ago,
Tom's age --> 1p
Sam's age --> 1u
Now,
Tom's age --> 3u
Sam's age --> 1p
Age difference remains the same, therefore,
1p-1u = 3u-1p
1p --> 2u
Now,
Tom's age --> 3u
Sam's age --> 2u
Total --> 5u --- 30
1u --> 6
Tom's age now --> 18
cheers. -
hi. Cld someone help me on this pls?
The ratio of the number of Donovan’s stickers to the number of Hong Yi’s stickers is 10:3. After Donovan gave hong Yi 1/5 of his stickers, hong Yi had 30 stickers less than Donovan. How many stickers did Donovan give to Hong yi?
thanks -
rzz:
At firsthi. Cld someone help me on this pls?
The ratio of the number of Donovan's stickers to the number of Hong Yi's stickers is 10:3. After Donovan gave hong Yi 1/5 of his stickers, hong Yi had 30 stickers less than Donovan. How many stickers did Donovan give to Hong yi?
thanks
Donovan 10u
Hong Yi 3u
1/5 of 10u = 2u
Donovan gave 2u to Hong Yi
In the end
Donovan 10u - 2u = 8u
Hong Yi 3u + 2u = 5u
Hong Yi had 30 stickers less than Donovan
8u - 5 u -> 30
3u -> 30
1u -> 10
No of stickers that Donovan gave to Hong yi was 2u -> 2*10 = 20