Q&A - PSLE Math

[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

[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.