# Thread: 4th grade o_O ?!?

1. ## 4th grade o_O ?!?

tonight my daughter brought home this problem and it's due by morning.

I personally think it unsolvable without college-level algebra, but obviously her teacher does not. I'd/We'd really appreciate any help anyone could give.

2. The Venn diagram is not shown.

3. ## It's in the attachment

in the attachment isn't it?

4. ## in case the attachment is bad... here's a pdf

in case the attachment is bad... here's a pdf

5. Originally Posted by mixedup
in case the attachment is bad... here's a pdf
a) X is part of both the basketball and soccer circles, but not part of the table-tennis circle. So X represents the number of pupils who are taking both basketball and soccer, but not table-tennis.

b) In brief note that Y is a part of all three circles. So Y represents the number of pupils participating in all three sports.

For the record, this is grade level Mathematics. Some applications of Venn diagrams can get complicated, but these are just basic definitions.

-Dan

6. ## Thanks but...

I think the teacher wants to know the VALUE of X and the VALUE of Y (this is Singapore Mathematics... they've been working with Venn diagrams since Primary 2)

7. Originally Posted by mixedup
I think the teacher wants to know the VALUE of X and the VALUE of Y (this is Singapore Mathematics... they've been working with Venn diagrams since Primary 2)
Wow,so advanced.No wonder Singaporeans are much better ahead of us in Malaysia.The syllabus is up to date.I still can remember i learn Venn diagram when i was in form1.I don't know that is equivalent to what level of learning age in Singapore.

8. Originally Posted by mixedup
I think the teacher wants to know the VALUE of X and the VALUE of Y (this is Singapore Mathematics... they've been working with Venn diagrams since Primary 2)
Whoops! Okay then, this is a bit higher level than I had thought.

And either I'm doing something wrong or the numbers in the problem aren't correct. I get a negative value for X. Here's the setup:

We know that the total number playing baseball is
$36 + 18 = 54$
from the table and
$22 + 9 + X + Y$
from the Venn diagram. So
$22 + 9 + X + Y = 54$

We also know that the total number playing soccer is
$49 + 14 + X + Y = 64 + 22$

and playing table-tennis is
$9 + 14 + Y = 22 + 28$

From this last equation we get Y:
$23 + Y = 50$

$-23 + 23 + Y = -23 + 50$

$Y = 27$

We may use either of the other two equations to get X:
$22 + 9 + X + Y = 54$

So
$22 + 9 + X + (27) = 54$

$58 + X = 54$

$-58 + 58 + X = -58 + 54$

$X = -4$
(The other equation gives the same result. It's consistent anyway!)

If I made a mistake somewhere, please let me know.

-Dan

9. ## haha (minus 4)

Yeah that's what I got too, that's why i came here for help... obviously the question is flawed. I'm going to write to her teacher and ask... WTF?

Hey, thanks for your help Greatly appreciated