Q&A - PSLE Math

[Spongy]

Hi I need help in a question. :thankyou:


1. Charlie and Diana had some stamps. Charlie had 70% of what Diana had at first. Charlie then gave Diana 60% of what he had. As a result, Diana had 912 more stamps than Charlie. How many stamps did Charlie have at first?

[MathIzzzFun]

Spongy:

Hi I need help in a question. :thankyou:


1. Charlie and Diana had some stamps. Charlie had 70% of what Diana had at first. Charlie then gave Diana 60% of what he had. As a result, Diana had 912 more stamps than Charlie. How many stamps did Charlie have at first?

Hi

At first,
Diana --> 50 units
Charlie --> 35 units, 30% of Charlie's stamps --> 21 units

In the end,
Diana --> 71 units }
Charlie --> 14 units } difference = 57 units
57 units --> 912
1 unit --> 16
35 x 16 = 560, Charlie had 560 stamps at first.

cheers.

[Bunny27]

MathIzzzFun:

Spongy:

Hi I need help in a question. :thankyou:


1. Charlie and Diana had some stamps. Charlie had 70% of what Diana had at first. Charlie then gave Diana 60% of what he had. As a result, Diana had 912 more stamps than Charlie. How many stamps did Charlie have at first?

Hi

At first,
Diana --> 50 units
Charlie --> 35 units, 30% of Charlie's stamps --> 21 units

In the end,
Diana --> 71 units }
Charlie --> 14 units } difference = 57 units
57 units --> 912
1 unit --> 16
35 x 16 = 560, Charlie had 560 stamps at first.

cheers.

Hi, someone pls help on this question:


1) Jack, Kristine and Lina painted some chairs for their school classrooms. Jack painted ½ of the numbers of the chairs.
Kristine and Lina painted the remaining number of chairs in the ratio of 3:5.
Jack painted 65 more chairs than Kristine.
(a) How many chairs did Jack and Lina paint together?
(b) The school would save $4 for every chair painted, what was the total savings for the school?

Thank you!

[isetan]

atutor2001:

isetan:

Thanks atutor2001,

Your brain is not decaying but rather an active one. Thanks for the ans.

Sorry, confirmed chopped chopped that my brain is decaying. My answer is wrong. What I have given was the total number of chairs and not the \"chairs arranged in row\".

So the correct answer is :
1 part (1/14) of total chair = 1 short row +32 = 16 + 32 = 48
Total chairs in rows = 14 - 1=13 parts = 48 x 13 =624

MathIzzFun's answer is the correct one. :salute:

Hi atutor2001, anyway good try, at least better than I...total decayed.

[Andrew Lee]

quote=\"MathIzzzFun\"]

Spongy:

Hi I need help in a question. :thankyou:


1. Charlie and Diana had some stamps. Charlie had 70% of what Diana had at first. Charlie then gave Diana 60% of what he had. As a result, Diana had 912 more stamps than Charlie. How many stamps did Charlie have at first?

Hi

At first,
Diana --> 50 units
Charlie --> 35 units, 30% of Charlie's stamps --> 21 units

In the end,
Diana --> 71 units }
Charlie --> 14 units } difference = 57 units
57 units --> 912
1 unit --> 16
35 x 16 = 560, Charlie had 560 stamps at first.

cheers.[/quote]


Hi, someone pls help on this question:


1) Jack, Kristine and Lina painted some chairs for their school classrooms. Jack painted ½ of the numbers of the chairs.
Kristine and Lina painted the remaining number of chairs in the ratio of 3:5.
Jack painted 65 more chairs than Kristine.
(a) How many chairs did Jack and Lina paint together?
(b) The school would save $4 for every chair painted, what was the total savings for the school?

Thank you![/quote]


Hello,
I got 3 questions need you guy help pls :

http://i47.tinypic.com/t7cw36.jpg\">

http://i49.tinypic.com/rhrjo2.jpg\">

http://i48.tinypic.com/iqkncx.jpg\">

[Andrew Lee]

Andrew Lee:

quote=\"MathIzzzFun\"]

Spongy:

Hi I need help in a question. :thankyou:


1. Charlie and Diana had some stamps. Charlie had 70% of what Diana had at first. Charlie then gave Diana 60% of what he had. As a result, Diana had 912 more stamps than Charlie. How many stamps did Charlie have at first?

Hi

At first,
Diana --> 50 units
Charlie --> 35 units, 30% of Charlie's stamps --> 21 units

In the end,
Diana --> 71 units }
Charlie --> 14 units } difference = 57 units
57 units --> 912
1 unit --> 16
35 x 16 = 560, Charlie had 560 stamps at first.

cheers.

Hi, someone pls help on this question:


1) Jack, Kristine and Lina painted some chairs for their school classrooms. Jack painted ½ of the numbers of the chairs.
Kristine and Lina painted the remaining number of chairs in the ratio of 3:5.
Jack painted 65 more chairs than Kristine.
(a) How many chairs did Jack and Lina paint together?
(b) The school would save $4 for every chair painted, what was the total savings for the school?

Thank you![/quote]


Hello,
I got 3 questions need you guy help pls :

http://i49.tinypic.com/rhrjo2.jpg\">

http://i48.tinypic.com/iqkncx.jpg\">[/quote]

http://i47.tinypic.com/t6uxyq.jpg\">

[kiasuaunt]

Andrew Lee:

Andrew Lee:

quote=\"MathIzzzFun\"][quote=\"Spongy\"]Hi I need help in a question. :thankyou:


1. Charlie and Diana had some stamps. Charlie had 70% of what Diana had at first. Charlie then gave Diana 60% of what he had. As a result, Diana had 912 more stamps than Charlie. How many stamps did Charlie have at first?

Hi

At first,
Diana --> 50 units
Charlie --> 35 units, 30% of Charlie's stamps --> 21 units

In the end,
Diana --> 71 units }
Charlie --> 14 units } difference = 57 units
57 units --> 912
1 unit --> 16
35 x 16 = 560, Charlie had 560 stamps at first.

cheers.

Hi, someone pls help on this question:


1) Jack, Kristine and Lina painted some chairs for their school classrooms. Jack painted ½ of the numbers of the chairs.
Kristine and Lina painted the remaining number of chairs in the ratio of 3:5.
Jack painted 65 more chairs than Kristine.
(a) How many chairs did Jack and Lina paint together?
(b) The school would save $4 for every chair painted, what was the total savings for the school?

Thank you![/quote]
Hello,
I got 3 questions need you guy help pls :

http://i49.tinypic.com/rhrjo2.jpg\">

http://i48.tinypic.com/iqkncx.jpg\">[/quote]

http://i47.tinypic.com/t6uxyq.jpg\">[/quote]

Hi - the last 2 questions look very familiar - my dd did it before - was going thru her file to doublecheck the ans - maybe u can tell me which exam paper ( Henry Park )?

[Neat]

tianzhu:

Neat:

Thanks a lot, tianzhu.

If unit method is to be used, which item is to be made constant?

Regards

Hi

Good Morning.

I am trying to understand “which item is to be made constant”. Could you help to elaborate on it?

Alternatively, you may also present the solution in “Units and Parts”.

The relationship between Edward and Sam is given.

Edward ------ 4 units
Sam ------- 3 units

We differentiate between Edward/Sam and Jason by using parts for Jason.

1 unit + 1 part ------- 837 – 648 ------- 189

3 units + 3 parts ------ 3*189 ------ 567 (total amount)

Sam’s money@first ------- 837 – 567 ------- 270

3 units ------- 270
1 unit ------- 90

Therefore, Edward’s money@first ------- 4*90 ------ 360

837 – 360 – 270 ------ 207 (Jason’s money@first)

Best wishes

[quote]Thanks tianzhu[/quote]

[AJH]

Hi -


Q. Jane and May share a box of beads. If Jane were to give 25% of her share to May, Jane would have half of May’s final share. If Jane were to give 16 beads to May, Jane would have 54 fewer beads than May. If they were to pack all their beads into boxes of 25 each, what is the least number of boxes required to pack all of them?

Thank you.

[Neat]

Hi!


I need explanation on the following question:

A large warehouse had a total of 2180 black, red and white T-shirts for sale. The ratio of the number of black T-shirts to the number of red T-shirts was 3:1. After 2/5 of the black T-shirts, 1/3 of the white T-shirts and none of the red T-shirts were sold on the first day, there were 1504 T-shirts left. How many red T-shirts did the warehouse have at first?

B : R : W Total
Before 3 : 1 : ? 2180
Sold -2/5 0 -1/3 676
After 3/5 1 2/3 1504

The working given in the paper is 6u + 1p = 676
12u + 2p = 676 x 2 = 1352
14u + 2p = 1504
2u = 1504-1352 = 152
5u = (152/2) x 5 = 380

My question is why 6u + 1p = 676? I thought we should find the
common factor for 2/5 and 1/3?

Please enlighten.
Thanks