Saturday, March 31, 2012

P6 whole numbers (heuristics: model)

There were 3 times as many apples as oranges.
After removing 106 apples and 14 oranges, there were 3 times as many oranges as apples left.
How many apples were there at first?

(Question from Bryan Chua)

Friday, March 30, 2012

P6 ratio (Heuristics: model and algebra )

Bobby had some red and blue marbles.
If 72 red marbles were removed, the ratio of the number red marbles to that of the blue marbles would be 1:2.
If 180 blue marbles were removed instead, the ratio would become 5:1.
How many red marbles were there?

(Adapted from a question from Bryan Chua)

Thursday, March 29, 2012

P6 Fractions (Heuristics: draw a diag)

Four children Andy, Benny, Candy and Diane each had some savings.
Benny had 1/3 of the total amount Candy and Diane had.
Diane had 1/4 of  the total amount Benny and Candy had.
Andy had 1/5 of the total amount Benny, Candy and Diane had.
Candy had $1067.
How much was the total savings of all the four children?

(Modified from Chloe Phang's question)

P6 Ratio (Heuristic: Guess-and-Check (GAC), Algebra, Area Diagram,)

Mrs Lim bought some forks and spoons in the ratio of 4:3.Each spoon cost 50 cents more than each fork.If she spent $156 altogether and the amount she spent on the forks was $12 more than the amount she spent on the spoons,how many forks and spoons did she buy?


(question from She Huiping dtd: Wed, Mar 28, 2012 at 5:58 PM)

Monday, March 5, 2012

P5 / P6 Ratio, Fraction (Fr: Jayden

1) The ratio of the number of Donovan's stickers to the number of Hong Yi's stickers is 10:3. After Donavan gave Hong Yi 1/5 of his stickers, Hong Yi had 30 stickers less than Donavan. How many stickers did Donovan give to Hong Yi

2) Class A and Class B have the same number of pupils. The ratio of the number of boys in Class A to the number of boys in Class B is 3:2. The ratio of the number of girls in Class A to the number of girls in Class B is 3:5. Find the ratio of the number of boys in Class A to the number of girls in Class B.
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Click here for my solution

Sunday, March 4, 2012

Saturday, March 3, 2012

P5, P6 Percentage

Hi mr chang,
Can you help me solve this question?

My salary is 1/5 more than my sister but 20% less than my brother.
If our total salary is $11100, what is my sister's salary.

Thanks,
Jayden