Hi, can someone help me with St Nicks 2011 P6 SA1 paper Q26. Can’t upload the document as I don’t have a scanner…appreciate it.

Hi Tianzhu, Small, MathIzzzFun, thank you so much for your help.

Hi, I need help on the following questions.


1) Tina paid a total of $336 for 2 similar dresses and a skirt after a discount of 20% was given on the price on each item. If the original price of each dresses was 25% more than that of the skirt, find the price of each dress before the discount

2) 30% of the beads from Box A were transferred to B. 2/5 of the beads frm box B was transferred to box A. Finally there were 416 beads in box A and this was 128 beads more than that in box B. What is the fraction of the beads was there in box A at first?

3)Lisa takes 4h to assemble a robot. Nancy takes 2 2/3h to assembler a similar robot (*h= HOURS)
(a) If Lisa works alone for the first 4h, Nancy joins her and both of them work together for the next 8h, how many such robots will they assemble then?
(b) Given that both of them work together from the beginning, how long do they take to assemble 40 such robots

4) Rohy has some goldfish and angelfish in his aquarium. 25% of all the fish are goldfish. Then he buys an equal number of goldfish and puts them into the aquarium.
(a) Will the % of all the fishes in the aquarium which are angelfish increase, decrease or remain the same (presume answer is decrease)
(b)What % of all the fish will be angelfish

5)Gina, Mary and Alyssa have some money. They want to buy a handbag for their mother. Gina has $30 more than Mary.
If Gina buys the handbag, the ratio of her money left to Mary and Alyssa will be 9:24:27 respectively.
If Mary buys the same handbag, the ratio of her money left to that of Gina and Alyssa will be 1:10:9 respectively.
If Alyssa buys the same handbag, the ratio of her money to that of Gina and Mary will be 1:5:4 respectively.
What is the cost of the handbag?

tianzhu:

homeworkmummy:

Thanks tianzhu. She is not familiar with the comparison method. Is this only cover in p6?

Hi

Good Morning.

You're welcome.

“Finding percentage increase/decrease” is only covered in P6 syllabus.

http://www.moe.gov.sg/education/syllabuses/sciences/files/maths-primary-2007.pdf

Best wishes

Thanks Tianzhu for the info.

tianzhu:

homeworkmummy:

Could you pls advise if this can be solved by model method. My DD was confused with the percentage method.

Hi

It’s possible to provide graphical representations of the information in the question.

Perhaps you may want to check with your DD.

What is confusing her?

What is her understanding of percentages after reading her textbooks?

What is her understanding on comparing two quantities of percentages?

Percentages is first started in P5 Maths.Maybe, she is confused because her teacher has not covered the topic in Percentages for her P6 syllabus yet.

Best wishes

Thanks tianzhu. She is not familiar with the comparison method. Is this only cover in p6?

tianzhu:

homeworkmummy:

I need help for another 1 Qs from Nan Hua paper.


Mrs Samy had a sum of money to spend. She spent 1/2 of her money plus $4 on a handbag. She then spent 1/2 of the remaining money plus $2 on a pair of shoes. Finally she spent 2/3 of what was left plus $1 on a skirt. She was then left with $11.
(a) How much did each item cost?
(b) How much money did she have at first?

Hi

You may use “Working backwards” and show it using MD.

1/3 ------- 11+1 ------ 12
3/3 -------12*3 ------ 36

36+2 ------ 38
38*2 ------ 76

76+4 ------80
80*2 ------ 160

Skirt ----- 24+1 ------ 25
Shoes ----- 38+2 ------ 40
Handbag --------80+4 ------84

Amount of money at first ------160

Best wishes

Thanks tianzhu for the help.

I need help for another 1 Qs from Nan Hua paper.


Mrs Samy had a sum of money to spend. She spent 1/2 of her money plus $4 on a handbag. She then spent 1/2 of the remaining money plus $2 on a pair of shoes. Finally she spent 2/3 of what was left plus $1 on a skirt. She was then left with $11.
(a) How much did each item cost?
(b) How much money did she have at first?

mathfreak:

Superbugs:

Nan Hua CA1 P6 2011

Q14.
My salary is 1/5 more than my sister but 20% less than my brother. If our total salary is $11,100, what is my sister's salary?

If Me=100%
Brother =120%
Sister=80%
80/300x11,100=2960
but answer is $3000?
Pls assist. Tks

Actually, if Me is 100%, Sister is not 80% (this means \"Me\" had 1/4 more than Sister), but instead is 100%*5/6=83 1/3%. This is so that 1/5 of Sister added to Sister will give \"Me\".
Brother is also not 120% (this means \"Me\" had 16 2/3% less than Brother), but instead is 100%*5/4=125%. This is so that 20% of Brother subtracted from Brother will give \"Me\".

The total would be 308 1/3%, which means 83 1/3% is $3000.

Could you pls advise if this can be solved by model method. My DD was confused with the percentage method.

Thanks MathIzzzFun.

MathIzzzFun:

homeworkmummy:

Hi pls help with the following question and thanks in advance.


1. Adrian, Brian and Charlie had some money. After spending a total of $2900, they each had the same amount of money left. Adrian spent 20% of his money, Brian spent 25% of his money and Charlie spent $464. What percentage of his money did Charlie spend?

2. Thomas has a total of 408 blue and yellow marbles. He lost 3/5 of his blue marbles and bought another 32 yellow marbles. As a result, the number of yellow marbles he had was 1/4 of the number of blue marbles. How many more blue marbles than yellow ones had he at first?

Hi
Q1.
In the end,
Adrian --> 12u
Brian --> 12u
Charlie --> 12u

At first,
Adrian --> 12 u + 3u = 15u
Brian --> 12u + 4u = 16u
Charlie --> 12u + $ 464

3u + 4u + $ 464 --> $ 2900
7u --> $ 2436
1u --> $ 348

At first, Charlie's money --> 12 x $ 348 + $ 464 = $ 4640
$ 464/$ 4640 x 100% = 10%
Charlie spent 10% of her money.


Q2.

In the end,
Yellow marbles --> 1u
Blue marbles --> 4u

At first,
Yellow marbles --> 1u - 32
Blue marbles --> 4u/2 x 5 = 10u
10u + 1u - 32 --> 408
11u --> 440
1u --> 40

10u - (1u-32) = 9u + 32 = 9 x 40 + 32 =392
There were 392 more blue marbles than yellow marbles at first.

cheers.

Thanks MathIzzzFun. For Q1 why do you start with 12u?