Q&A - P3 Math

[bluesclue]

Hi,


Can anyone help me with this question?

Mass of a glass of water =400g. After emptying half the water, the mass =240g.

Question: what is the mass of the empty glass?

Thank you.

[CMF]

bluesclue:

Mass of a glass of water =400g. After emptying half the water, the mass =240g.


Question: what is the mass of the empty glass?

If after emptying half the water, the mass (of the remaining half water + glass) = 240g

Then it means half of the water emptied = 160g (400g - 240g)

Therefore full glass of water (without the glass) : 160g x 2 = 320g

The empty glass itself would be : 400g - 320g = 80g

[bluesclue]

CMF:

bluesclue:

Mass of a glass of water =400g. After emptying half the water, the mass =240g.


Question: what is the mass of the empty glass?

If after emptying half the water, the mass (of the remaining half water + glass) = 240g

Then it means half of the water emptied = 160g (400g - 240g)

Therefore full glass of water (without the glass) : 160g x 2 = 320g

The empty glass itself would be : 400g - 320g = 80g

CMF,
Thanks for your post. The model answer given is 40g. Any thoughts why?

[Taurus]

Hi,


Anyone can assist on this qns:

The larger of two numbers is four more than three times the smaller number. The sum of the two numbers is 28. What is the smaller number?
1) 4
2) 6
3) 7
4) 8

Thanks

[kwcllf]

Taurus:

Hi,


Anyone can assist on this qns:

The larger of two numbers is four more than three times the smaller number. The sum of the two numbers is 28. What is the smaller number?
1) 4
2) 6
3) 7
4) 8

Thanks

Small Number ----> 1u
Big Number -------> (3 x 1u) + 4

Sum of Small Number + Big Number = 28
------> 1u + 3u + 4 = 28
------> 1u = 6

Therefore, Small Number = 6

[Taurus]

kwcllf:

Taurus:

Hi,


Anyone can assist on this qns:

The larger of two numbers is four more than three times the smaller number. The sum of the two numbers is 28. What is the smaller number?
1) 4
2) 6
3) 7
4) 8

Thanks

Small Number ----> 1u
Big Number -------> (3 x 1u) + 4

Sum of Small Number + Big Number = 28
------> 1u + 3u + 4 = 28
------> 1u = 6

Therefore, Small Number = 6

Thanks a lot

[fohope]

Hi,

Pls help me solve this question. Thanks in advance for your contribution and time.

Tao Nao 2011-Mid year Exam
Jack sold a total of 285 apples and pears.
He sold twice as many apples as pears.
How many more apples than pears di he sell?

[tianzhu]

fohope:

Hi,

Pls help me solve this question. Thanks in advance for your contribution and time.

Tao Nao 2011-Mid year Exam
Jack sold a total of 285 apples and pears.
He sold twice as many apples as pears.
How many more apples than pears di he sell?

Hi

You may use MD.

Apples ------ 2 units
Pears ------- 1 unit

3 units ------- 285
1 unit ------- 95

He sold 95 more apples than pears.

Best wishes

[HAPPYH]

bluesclue:

CMF:

[quote=\"bluesclue\"] Mass of a glass of water =400g. After emptying half the water, the mass =240g.


Question: what is the mass of the empty glass?

If after emptying half the water, the mass (of the remaining half water + glass) = 240g

Then it means half of the water emptied = 160g (400g - 240g)

Therefore full glass of water (without the glass) : 160g x 2 = 320g

The empty glass itself would be : 400g - 320g = 80g

CMF,
Thanks for your post. The model answer given is 40g. Any thoughts why?[/quote]Hi
I am not sure you (or the teacher) modified this question. There is a similar question in P3 My pals workbook but the numbers are different.

Mass of a glass of water =200g. After emptying half the water, the mass =120g.
If you use these numbers the answer will be 40 g (mass of empty glass). Somehow your question has the double of these numbers so the mass of empty glass should be 80g (everything doubled).

Hope this helps!

[bluesclue]

Hi, Yes, numbers were changed as you have noticed. with 200g/ 120g for full/half glass , DS's answer for the empty glass was 40g, but teacher marked it as wrong and said answer should be 20g. :? So just wanted to find out if our understanding is correct. With CMF and your confirmation, i think 40g should be the right answer, thanks.