Q&A - PSLE Math

[Shimmer]

Need help !


1 . Mr Wang bought 4 times as many chairs as tables. He spent $2527 altogether. A table cost $13 more than a chair. The total cost of the chairs was $1121 more than the total cost of the tables.
A) how much dud he spend on tables ?
B) find the cost of each table

[KPLEE]

Shimmer:

Need help !


1 . Mr Wang bought 4 times as many chairs as tables. He spent $2527 altogether. A table cost $13 more than a chair. The total cost of the chairs was $1121 more than the total cost of the tables.
A) how much dud he spend on tables ?
B) find the cost of each table

Use \"stacking\" method
A) (2527-1121)/2= 703
B) chairs=2527-703=1823
1824/4units= 456 cost of 1 stack of chairs
703-456=247 difference bet 1 stack of T v. C
247/13=19tables
703/19=37 each

[susutoo]

please help:-)

There were 315 more adults than children at an exhibition at first. After 1/7 of the adults and 60% of the children left the exhibition, there were 462 more adults than children at the exhibition. How many people were at the exhibition at first.

[Recia Lim]

tianzhu:

Recia Lim:

Please help to solve this speed question. Thanks!

Question: Mrs Tan took 40 min to walk from her home to the market. On her return journey, she took an additional 8 min. her speed on the way back was 1km/h slower. What was the distance between her home and the market?

Hi

There are a few ways to do this question.

For this question, students may get their answers quickly using GC.

Another possibility is to use inverse proportion if students are familiar with it.

Given the same distance, speed is inversely proportional to time.

Higher speed needs less time.

Lower speed leads to more time.

Time ratio

40:48 ------- 5:6

Speed ratio ------- 6:5

1 unit ------ 1 km/h

5 units ------ 5 km/h

Distance between her home and the market ------- 5*48/60 ------- 4 km

Alternatively you may use the faster speed of 6 km/h

In this case, 6*40/60 ------ 4 km.

Best wishes

Thanks! How do we know when should we use this inverse proportion method?

[xiaotiao]

Can anyone help me to solve this problem, thanks!!!


The average weight of a group of boys is 50kg. If one more boy who weighs 76 kg joins the group, the average of weight will become 52kg. Find the number of boys in the group.

Hopefully a kind soul can do me a favour.

[Michaelia0816]

Tianzhu,

Pls help with this question. I do not understood the (a) part by http://2.bp.blogspot.com/_NGNaLTzN5_U/SrxBdiupjrI/AAAAAAAADz0/SzuIy0v5zX0/s1600-h/Maths0609SA2P2NYSpeedQ17A.JPG.

1) Ali saved some money in the form of $2, $5 and $10 notes. The value of the $2, $5 and $10 was in the ratio of 3:10 : 5. After taking out 2/3 of the $2 notes and 16 of the $5 notes to pay for a trip to China ,he had $2400 left. Find the value of the $10 notes that he had saved. ( Can I ask for the last step, I not sure if it is $1550 or $775)

[zanen]

tianzhu:

zanen:

mind helping with this question? thankyou. :)There is a big migic fruit tree in a garden. It bears fruits at a constant rate every day. Man will pick the fruits and sell. Animals will pluck and eat the fruits. 25 men can pick all the fruits in 15 days and 66 animals can eat all the fruits in 10 days. If 1 man can pick twice the number of fruits as 1 animal, find the number of days it take for 10 men to pick and 10 animals to eat all the fruits together?

Hi

Is this a PSLE type of question?

The answer to this question is 40 days.

How do you get the answer? mind sharing?

Best wishes

[Michaelia0816]

Recia Lim:

tianzhu:

[quote=\"Recia Lim\"]Please help to solve this speed question. Thanks!

Question: Mrs Tan took 40 min to walk from her home to the market. On her return journey, she took an additional 8 min. her speed on the way back was 1km/h slower. What was the distance between her home and the market?

Hi

There are a few ways to do this question.

For this question, students may get their answers quickly using GC.

Another possibility is to use inverse proportion if students are familiar with it.

Given the same distance, speed is inversely proportional to time.

Higher speed needs less time.

Lower speed leads to more time.

Time ratio

40:48 ------- 5:6

Speed ratio ------- 6:5

1 unit ------ 1 km/h

5 units ------ 5 km/h

Distance between her home and the market ------- 5*48/60 ------- 4 km

Alternatively you may use the faster speed of 6 km/h

In this case, 6*40/60 ------ 4 km.

Best wishes

Thanks! How do we know when should we use this inverse proportion method?[/quote]When the question asked you about the time and speed.

[Michaelia0816]

Michaelia0816:

Tianzhu,

Pls help with this question. I do not understood the (a) part by http://2.bp.blogspot.com/_NGNaLTzN5_U/SrxBdiupjrI/AAAAAAAADz0/SzuIy0v5zX0/s1600-h/Maths0609SA2P2NYSpeedQ17A.JPG.

1) Ali saved some money in the form of $2, $5 and $10 notes. The value of the $2, $5 and $10 was in the ratio of 3:10 : 5. After taking out 2/3 of the $2 notes and 16 of the $5 notes to pay for a trip to China ,he had $2400 left. Find the value of the $10 notes that he had saved. ( Can I ask for the last step, I not sure if it is $1550 or $775)

Pls help me!

[whitety]

susutoo:

please help:-)

There were 315 more adults than children at an exhibition at first. After 1/7 of the adults and 60% of the children left the exhibition, there were 462 more adults than children at the exhibition. How many people were at the exhibition at first.

My dd's method. Hope you understand the solution.

60/100=6/10=42/70
1/7=10/70

At first
A:C
70u+315:70u

1/7*(70u+315)=10u+45
42/70*70u=42u

Went away
A:C
10u+45:42u

In the end
A:C
60u+270:28u<---diff of 462
60u-28u=32u
462-270=192(32u)
1u=6
70u+70u+315=1155
Cheers :celebrate: