Q&A - PSLE Math

[tianzhu]

Vanilla Cake:

I had tried to post this diagram but the size was too big. How do you control the size of the image/diagram that you want to post here?.

Hi VC

For Flickr, you can select the sizes,small,medium,large.
I am not familiar with the other storage media.

Best wishes

[abc_parent]

Hi all


I am not sure about Q12, 13, 14 and Q18.

Q12) Tank P was filled with water as shown in the diagram (pls help with this if you have the diagram). Water was then poured from Tank P to Tank Q until the height of the water level in Tank P became twice that of the water level in Tank Q. Find the volume of water in Tank Q. Given your answers in litres.

Q13) A van travelled from Town A to Town B at an average speed of 55 km/h. A car started its journey from Town B to Town A at the same time as the van travelling at an average speed of 90km/h. The two vehicles passed each other 70 km from the middle of the whole journey. Find the distance between the two towns.

Q14) Cinema admission tickets for children were priced at $8 each. There were 20 more boys than girls in the cinema for the first movie. For the second movie, the number of boys decreased by 10% but the number of girls increased by 5%. If there were 408 children at the second movie, how much money was collected from the sales of admission tickets for the first movie?

Q18) (this question also has a diagram, please help if you have it) The shaded figure below is formed by a semi circle and quarter circle. It lies within rectangle PQRS in which RU = 1cm, UQ = 2 cm, PT = 3 cm.
(a) Find the perimeter of the shaded region. Give your answer in terms of pi.
(b) Find the area of the shaded region. Give your answer correct to 2 decimal places.[/b]

[Vanilla Cake]

abc_parent:

Hi all


I am not sure about Q12, 13, 14 and Q18.

Q12) Tank P was filled with water as shown in the diagram (pls help with this if you have the diagram). Water was then poured from Tank P to Tank Q until the height of the water level in Tank P became twice that of the water level in Tank Q. Find the volume of water in Tank Q. Given your answers in litres.

Q13) A van travelled from Town A to Town B at an average speed of 55 km/h. A car started its journey from Town B to Town A at the same time as the van travelling at an average speed of 90km/h. The two vehicles passed each other 70 km from the middle of the whole journey. Find the distance between the two towns.

Q14) Cinema admission tickets for children were priced at $8 each. There were 20 more boys than girls in the cinema for the first movie. For the second movie, the number of boys decreased by 10% but the number of girls increased by 5%. If there were 408 children at the second movie, how much money was collected from the sales of admission tickets for the first movie?

Q18) (this question also has a diagram, please help if you have it) The shaded figure below is formed by a semi circle and quarter circle. It lies within rectangle PQRS in which RU = 1cm, UQ = 2 cm, PT = 3 cm.
(a) Find the perimeter of the shaded region. Give your answer in terms of pi.
(b) Find the area of the shaded region. Give your answer correct to 2 decimal places.[/b]

Hi abc_parent,
Here's the online version of the http://www.orlesson.org/orp/09Ma/2009-P6-Math-SA2-HenryPark.pdf.Sorry, I am busy working on the 2010 P6 Prelim Maths exam papers and pls wait for other KSP members to help.

You wish wish to http://prischoolmaths.blogspot.com/2009/09/henry-park-speed.html for your Q13 on speed.http://4.bp.blogspot.com/_NGNaLTzN5_U/SrTHBF0N2oI/AAAAAAAADws/wAhKWR0oCIk/s1600-h/Maths0609SA2P2HPCicrleQ18A.JPG for your Q18.I think it's good if you can type out the given answer for the question as it will save time for the potential problem solvers. Just my 2 cents.

[Vanilla Cake]

Susan has some vanilla and chocolate sweets in her bag. If she adds 20 vanilla sweets into the bag, the percentage of vanilla sweets in the bag becomes 40%. If she adds 30 chocolate sweets, there will be 70% of chocolate sweets in the bag. How many vanilla and chocolate sweets does she have? [5 marks][Answer given: 64 vanilla sweets and 126 chocolate sweets]


Thank you for your time and effort. I appreciate your help as I think that the answer given is incorrect.

My answers are : Vanilla sweets: 72 and Chocolate sweets: 138
Took me about 10 min plus using 2 different methods to crack this problem sum.Pls help to clarify if I am correct or the given answer is correct.

[tianzhu]

Vanilla Cake:

My answers are : Vanilla sweets: 72 and Chocolate sweets: 138
Took me about 10 min plus using 2 different methods to crack this problem sum.Pls help to clarify if I am correct or the given answer is correct.

Hi VC

You're are correct.

Best wishes

[Vanilla Cake]

tianzhu:

Vanilla Cake:

My answers are : Vanilla sweets: 72 and Chocolate sweets: 138

Took me about 10 min plus using 2 different methods to crack this problem sum.Pls help to clarify if I am correct or the given answer is correct.

Hi VC

You're are correct.

Best wishes

Thks, Uncle Tianzhu for your confirmation.Now, I am working on these 10 Maths papers from 2010 P6 Prelim. Definitely, the level of P6/PSLE Maths is getting higher nowadays than my good old days when I took PSLE Maths 2008.

[kancheongmum]

Hi Tianzhu

Ha ha did not realize the time when I worked on the solution. I just got the papers yesterday and looking through them first before I let ds try. You are right, is definitely worth looking through these papers. Spent only $35 for 3 subjects. DH out of job for 6 mths already cannot afford tuition. Looking at how much tuition centre charged for intensive psle revision this is only a small fraction. I had paid a private maths tutor $100/h before but stop after 4 mths as it did not work well. I am still the best and free tutor. Big thank to all the helpful souls like you, Dharma and others. So willing the help anytime without the $$$$ attached.

Here is another problem:

In a group of 36 students, the number of students who like sushi is thrice the number of students who like nuggets. If 2 students like neither sushi nor nuggets and 6 students like both, how many students like nuggets? (ans 10)

[corneyAmber]

kancheongmum:

Here is another problem:

In a group of 36 students, the number of students who like sushi is thrice the number of students who like nuggets. If 2 students like neither sushi nor nuggets and 6 students like both, how many students like nuggets? (ans 10)

S [ ] [ ] [ 6] = 3 parts
N [ 6] = 1 part
None [2]

Total = 36
So subtracting the students who like neither = 36 -2 = 34

(3parts - 6) + (1 part - 6) -> 34 - 6
4 parts - 12 -> 28
4 parts -> 40
1 part -> 10

Nuggets -> 1 part

Hence the number of students who like nuggets is 10.

[Vanilla Cake]

kancheongmum:

In a group of 36 students, the number of students who like sushi is thrice the number of students who like nuggets. If 2 students like neither sushi nor nuggets and 6 students like both, how many students like nuggets? (ans 10)

Hi kancheongmum,
While waiting for Uncle Tianzhu / Uncle Dharma, here's my amateurish solution:

Sushi : Nuggets:
3u : u

Draw a venn diagram if necessary to help you under better.
The overlapping of 2 circles is 6 students who like both.
For the \"sushi\" circle minus the overlapping area -> 3u-6
and for the \"nuggets\" circle minus the overlapping area -> u-6

36-2=34 (2 students like neither sushi or nuggets)

3u-6+6+u-6=34
4u-6=34
4u=40
u = 10

10 students like nuggets.

[Yu Xuan]

kancheongmum:

Hi Tianzhu

Here is another problem:

In a group of 36 students, the number of students who like sushi is thrice the number of students who like nuggets. If 2 students like neither sushi nor nuggets and 6 students like both, how many students like nuggets? (ans 10)

Students who like either sushi or nuggets or both...
36 - 2 = 34

By adding another 6 to 34, it will become 3 units + 1 unit = 4 units
34 + 6 = 40 (4 units)
1 unit --> 40 / 4 = 10