Q&A - PSLE Math

[corneyAmber]

abc_parent:

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?

Girls [ ] ---> 1 part
Boys [ ] [20] ---> 1 part + 20

At second movie, after the increase and decrease of girls and boys,

1.05 (1 part) + 0.9 (1 part + 20) -> 408
1.05 part + 0.9 part + 18 -> 408
1.95 part -> 390
1 part -> 200

Hence children at first movie -> 200 + 200 + 20 = 420

Total amount collected at first movie = 420 * $8 = $3360

[Yu Xuan]

This is really amazing, each showing their own way of solving a problem and the child can choose the method that he/she understands best.


Bless all u wonderful people.

[Dharma]

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)

3u + 1u - 6 = 36 - 2
4u = 40
1u = 10
No.of students who like nuggets = 1u = 10

[corneyAmber]

Yu Xuan:

This is really amazing, each showing their own way of solving a problem and the child can choose the method that he/she understands best.


Bless all u wonderful people.

Hi Yu Xuan,

Are you the P5/P6 girl I recently saw in a Math competition in Kovan?

[kancheongmum]

hi all tks for the solutions

[Yu Xuan]

ksi:

Yu Xuan:

This is really amazing, each showing their own way of solving a problem and the child can choose the method that he/she understands best.


Bless all u wonderful people.

Hi Yu Xuan,

Are you the P5/P6 girl I recently saw in a Math competition in Kovan?

Hi

Nope, I'm a mum. Sometimes my son uses my name to answer the questions too.

[Vanilla Cake]

Hi Uncle Tianzhu / Uncle Dharma,


Could you pls spare time to look into part (b) of http://psle2010a.blogspot.com/2010/09/volume-p6-2010-maha-bodhi-p2-q13.html and express your comments.The answer given for (b) is 56.25
Thanks.

[Vanilla Cake]

abc_parent:

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.

http://www.orlesson.org/orp/09Ma/2009-P6-Math-SA2-HenryPark.pdf
Suggested solution
Original volume of water in tank P = 55cmx40cmx30cm = 66000 cm³
Assume the height of water in Tank Q be h,
New volume of water in tank P = 2h cmx40cmx30cm=2400h cm³
New volume of water in tank Q = h cmx100cmx20cm = 2000h cm³
2400h + 2000h = 66000
4400h = 66000
h = 15

New volume of water in Tank Q = 15cmx100cmx20cm = 30000 cm³ = 30 litres.
Volume of water in Tank Q = 30 litres.

PS: If there is given answer, pls state it together with the question. Does not matter if it's 100% or not, the given answer is for reference purpose.

[Dharma]

Vanilla Cake:

Hi Uncle Tianzhu / Uncle Dharma,


Could you pls spare time to look into part (b) of http://psle2010a.blogspot.com/2010/09/volume-p6-2010-maha-bodhi-p2-q13.html and express your comments.The answer given for (b) is 56.25
Thanks.

Hi VC,

Definately there is lack of info from what I read from the qn in Observer's blog. I don't have the actual papers to check the actual wordings on the qn.

[tianzhu]

Vanilla Cake:

Hi Uncle Tianzhu / Uncle Dharma,

Could you pls spare time to look into part (b) of http://psle2010a.blogspot.com/2010/09/volume-p6-2010-maha-bodhi-p2-q13.html and express your comments.The answer given for (b) is 56.25
Thanks.

Hi VC

There may be some missing information.

Best wishes