Q&A - PSLE Math

[carebear]

2nd question solved.

Sorry for the poor quality cos I am too tired :snooze:.

http://www.flickr.com/photos/63342911@N03/6093193929/

[stary]

Thanks carebear!!!

[SaPan]

tianzhu:

SaPan:

some workers arranged chairs in 18 short rows and 7 long rows.
each long row had 32 more chairs than short rows.
half of the chairs were arranged in long rows while 3/7 of the chairs in short rows.
remaining chairs are stacked in a corner.

How many chairs were arranged in rows?

Hi

Long rows (LR) ------ 7 units (1/2 of 14)
Short rows (SR) ------ 6 units (3/7 0f 14)
Stacked up chairs ------ 1 unit

6 units ------ 18SR
1 unit ------ 3SR

1LR ------ 1SR + 32
7LR ------ 7SR + (7*32) ------7SR + 224

You may use MD to compare
7SR + 224 ------- 18SR + 3SR
14SR ----- 224
1SR ----- 16
\t
1 unit ---- 3SR ----- 48
13 units ----- 13*48 -------- 624

Number of chairs (rows) ------ 624

Best wishes

thank you so much tianzhu. :salute:

[Snowball99]

carebear:

stary:

Hi all, need help for the following questions


1) Mrs Yeo had 20% more books than Mdm Lim. Miss Tang had 40% fewer books than Mrs Yeo. Mrs Yeo and Mdm Lim gave Miss Tang some books in the ratio of 1:2. As a result, Miss Tang had 50% more books than before. Given that Miss Tang had 96 more books than Mdm Lim in the end, how many books did Miss Yeo give to Miss Tang?

2)Last Monday morning, Edward walked from home to school. For the first 2 minutes, he was walking at an average speed og 40m/min. When he realised that he was going to be late by 3 minutes, he quickly increased his speed by 10m/min. As a result, he was early be 1 minute. Find the distance between his home to his school.

I think you should use the ratio of speed and time. (inversely related)


Speed:
4:5
Time:
5:4
The difference between the times is 4 minutes.
Thus, 1u time = 4 min
So,
5u= 20 min
Distance= 40m/min for 20 min
= 800m

Managed to do 1st question only.


http://www.flickr.com/photos/63342911@N03/6093555012/

[Snowball99]

Snowball99:

carebear:

[quote=\"stary\"]Hi all, need help for the following questions


1) Mrs Yeo had 20% more books than Mdm Lim. Miss Tang had 40% fewer books than Mrs Yeo. Mrs Yeo and Mdm Lim gave Miss Tang some books in the ratio of 1:2. As a result, Miss Tang had 50% more books than before. Given that Miss Tang had 96 more books than Mdm Lim in the end, how many books did Miss Yeo give to Miss Tang?

2)Last Monday morning, Edward walked from home to school. For the first 2 minutes, he was walking at an average speed og 40m/min. When he realised that he was going to be late by 3 minutes, he quickly increased his speed by 10m/min. As a result, he was early be 1 minute. Find the distance between his home to his school.[/quote

I think you should use the ratio of speed and time. (inversely related) for the 2nd question.

Speed:
4:5
Time:
5:4
The difference between the times is 4 minutes.
Thus, 1u time = 4 min
So,
5u= 20 min
Distance= 40m/min for 20 min
= 800m

Cheers,
Snowball99




http://www.flickr.com/photos/63342911@N03/6093555012/

[/quote]

[stary]

Snowball99:

carebear:

[quote=\"stary\"]Hi all, need help for the following questions


1) Mrs Yeo had 20% more books than Mdm Lim. Miss Tang had 40% fewer books than Mrs Yeo. Mrs Yeo and Mdm Lim gave Miss Tang some books in the ratio of 1:2. As a result, Miss Tang had 50% more books than before. Given that Miss Tang had 96 more books than Mdm Lim in the end, how many books did Miss Yeo give to Miss Tang?

2)Last Monday morning, Edward walked from home to school. For the first 2 minutes, he was walking at an average speed og 40m/min. When he realised that he was going to be late by 3 minutes, he quickly increased his speed by 10m/min. As a result, he was early be 1 minute. Find the distance between his home to his school.

I think you should use the ratio of speed and time. (inversely related)


Speed:
4:5
Time:
5:4
The difference between the times is 4 minutes.
Thus, 1u time = 4 min
So,
5u= 20 min
Distance= 40m/min for 20 min
= 800m

Managed to do 1st question only.


http://www.flickr.com/photos/63342911@N03/6093555012/

[/quote]Thanks Snowball99... (you've got the arragement wrong)

[tianzhu]

SaPan:

thank you so much tianzhu. :salute:

Hi

Good Morning.

You're welcome.

Best wishes

[carebear]

stary:

Thanks Snowball99... (you've got the arragement wrong)

I think what Snowball99 actually wanted to post is this :

Snowball99:

stary:

Hi all, need help for the following questions

1) Mrs Yeo had 20% more books than Mdm Lim. Miss Tang had 40% fewer books than Mrs Yeo. Mrs Yeo and Mdm Lim gave Miss Tang some books in the ratio of 1:2. As a result, Miss Tang had 50% more books than before. Given that Miss Tang had 96 more books than Mdm Lim in the end, how many books did Miss Yeo give to Miss Tang?

2)Last Monday morning, Edward walked from home to school. For the first 2 minutes, he was walking at an average speed og 40m/min. When he realised that he was going to be late by 3 minutes, he quickly increased his speed by 10m/min. As a result, he was early be 1 minute. Find the distance between his home to his school.

carebear:

2nd question solved.
Sorry for the poor quality cos I am too tired .

http://www.flickr.com/photos/63342911@N03/6093193929/

I think you should use the ratio of speed and time. (inversely related)


Speed:
4:5
Time:
5:4
The difference between the times is 4 minutes.
Thus, 1u time = 4 min
So,
5u= 20 min
Distance= 40m/min for 20 min
= 800m

[gijg]

Hi ,


I need some help with this speed question:
Mike and Steve started jogging at the same time from pt A to pt B , respectively along a running track in opp direction . Mike met Steve when he is 8km from A . Both of them turn back after reaching A and B . They met again at 4km from B. Find the dist from pt A to pt B .

Thank you .

[carebear]

gijg:

Hi ,


I need some help with this speed question:
Mike and Steve started jogging at the same time from pt A to pt B , respectively along a running track in opp direction . Mike met Steve when he is 8km from A . Both of them turn back after reaching A and B . They met again at 4km from B. Find the dist from pt A to pt B .

Thank you .

Not enough info given.
Is the speed of Mike and Steve specified in the question?
Do we assume they are jogging at the same speed?