## Q&A - PSLE Math

### Re: Q&A - PSLE Math

Gold : Silver : Copper

32 : 40 : 18

40u - 18u -> 22u

22u->66

u->3

32+40+18=90

90×3 =270

Amended. Sorry for the careless mistakes.

32 : 40 : 18

40u - 18u -> 22u

22u->66

u->3

32+40+18=90

90×3 =270

Amended. Sorry for the careless mistakes.

Last edited by whywhy on Sun Mar 06, 2016 8:00 am, edited 1 time in total.

### Re: Q&A - PSLE Math

Thanks and appreciate your help and providing the answers .EconsPhDTutor wrote:The answer to the first question (gold, silver, copper coins) is 270. Please see this PDF for the full solution.ozora wrote:Need some help in the following questions.

The answers to the second question (Jason's marbles) are (a) 60; and (b) 14.3%. Please see this PDF for the full solution.

www.EconsPhDTutor.com

However, the students in p6 will be hard to formulate the simultaneous equations

Would be prefer to use methods that are easier for them to comprehend n apply.

Thanks again.

### Re: Q&A - PSLE Math

Thanks I also not sure of the answers. It was given my nephew's teacher.whywhy wrote:I try. Let me know if my ans is correct or not.

Red ->3u x 7 -> 21u

Green + Blue ->2u x 7 -> 14u

Green : Blue

9 : 5 ->14u

21u - 5u -> 192

u ->12

21u -> 21x12 =252

70% ->252

1%->252÷70=3.6

30%-> 3.6×30 = 108

14u -> 14x12= 168

168-108=60

a) 60

Total 35u x 12 =420

60÷420x100= 14.3%

b)14.3%

### Re: Q&A - PSLE Math

Unit method.ozora wrote: Thanks and appreciate your help and providing the answers .

However, the students in p6 will be hard to formulate the simultaneous equations

Would be prefer to use methods that are easier for them to comprehend n apply.

Thanks again.

Let the total coins be 100u

Copper is 20% of total coins, therefore = 20u

Silver = 20u + 66

Gold = 4/5 (20u + 66) = 16u + 52.8

Total = 100u

100u = copper + Silver + Gold

100u = 20u + (20u+66) + (16u+52.8)

100u = 56u + 118.8

44u = 118.8

u = 2.7

Altogether there are 100u coins = 100 X 2.7 = 270 coins#

### Re: Q&A - PSLE Math

Green : Blue => 9 : 5ozora wrote: Thanks and appreciate your help and providing the answers .

However, the students in p6 will be hard to formulate the simultaneous equations

Would be prefer to use methods that are easier for them to comprehend n apply.

Thanks again.

Let,

Blue =5u

Green 9u

Green + Blue = 14u

Since red is 3/5 or 60% of total, that makes Green + Blue =>40%

40% => 14u

100% = > 35u

Therefore red = 21u (60% of 35)

Findning u,

21u - 5u = 16u = 192 marbles (Red - Blue)

u = 12

Key point: Constant Red marbles.

After giving away some green, red is now 70% of total

70% = >21u

100% => 30u (The new total)

Green marble given away = 35u -30u =5u = 5 X 12 = 60 marbles

Percentage decrease = (5u/35u X 100) = 14.3%

### Re: Q&A - PSLE Math

thanks a lot @ Ender. appreciateEnder wrote:Green : Blue => 9 : 5ozora wrote: Thanks and appreciate your help and providing the answers .

However, the students in p6 will be hard to formulate the simultaneous equations

Would be prefer to use methods that are easier for them to comprehend n apply.

Thanks again.

Let,

Blue =5u

Green 9u

Green + Blue = 14u

Since red is 3/5 or 60% of total, that makes Green + Blue =>40%

40% => 14u

100% = > 35u

Therefore red = 21u (60% of 35)

Findning u,

21u - 5u = 16u = 192 marbles (Red - Blue)

u = 12

Key point: Constant Red marbles.

After giving away some green, red is now 70% of total

70% = >21u

100% => 30u (The new total)

Green marble given away = 35u -30u =5u = 5 X 12 = 60 marbles

Percentage decrease = (5u/35u X 100) = 14.3%

- mathsolversg
- KiasuNewbie
**Posts:**2**Joined:**Wed Mar 09,

### Re: Q&A - PSLE Math

Hi all lovely parents,

I have recently started a blog for my students to help them regarding their math questions. Decided to open it to public so please do give it a try. More questions solved = more learning done! Clear and concise solutions are provided with explanations wherever necessary! Just email the blog and I will post the solution ASAP. Please do tell me whether it's a p6 or sec 1 question so I can archive everything clearly for your own future references!

http://www.mathsolversg.blogspot.com

Cheers

I have recently started a blog for my students to help them regarding their math questions. Decided to open it to public so please do give it a try. More questions solved = more learning done! Clear and concise solutions are provided with explanations wherever necessary! Just email the blog and I will post the solution ASAP. Please do tell me whether it's a p6 or sec 1 question so I can archive everything clearly for your own future references!

http://www.mathsolversg.blogspot.com

Cheers

### Re: Q&A - PSLE Math

Hi,

Can someone help on the following questions with clear explanation? Thank you.

Q1) May, Susan, Ben and Joey, each have some stickers. May has 50% as many stickers as the total number of stickers that Susan, Ben and Joey have. The number of stickers that Susan has is 25% of the total number of stickers that May, Ben and Joey has. The number of stickers that Ben has is 2/3 of the total number of stickers that May, Susan and Joey has. If May gives 20 stickers to Susan, May and Susan will then have an equal number of stickers. Find the average number of stickers each of them has.

Q2) In a donation drive, Ali, Hendri, Danny and Kaviin collected an average of $128. Ali collection 1/7 of the total amount collected by Hendri, Danny and Kaviin. Hendri collected 2/5 of the total amount collected by Danny and Kaviin. Danny collected 1/3 as much donations as Kaviin. How much donations did Ali collect?

Q3) A wallet contained some 2-dollar and 5-dollar notes in the ratio of 8:3. When 15 2-dollar notes were taken out and replaced with some 5-dollar notes, there was 16% less 5-dollar notes than 2-dollar notes. The total value of all the notes remained the same. What is the total value of all the notes in the wallet?

Can someone help on the following questions with clear explanation? Thank you.

Q1) May, Susan, Ben and Joey, each have some stickers. May has 50% as many stickers as the total number of stickers that Susan, Ben and Joey have. The number of stickers that Susan has is 25% of the total number of stickers that May, Ben and Joey has. The number of stickers that Ben has is 2/3 of the total number of stickers that May, Susan and Joey has. If May gives 20 stickers to Susan, May and Susan will then have an equal number of stickers. Find the average number of stickers each of them has.

Q2) In a donation drive, Ali, Hendri, Danny and Kaviin collected an average of $128. Ali collection 1/7 of the total amount collected by Hendri, Danny and Kaviin. Hendri collected 2/5 of the total amount collected by Danny and Kaviin. Danny collected 1/3 as much donations as Kaviin. How much donations did Ali collect?

Q3) A wallet contained some 2-dollar and 5-dollar notes in the ratio of 8:3. When 15 2-dollar notes were taken out and replaced with some 5-dollar notes, there was 16% less 5-dollar notes than 2-dollar notes. The total value of all the notes remained the same. What is the total value of all the notes in the wallet?

- teacherstorie
- KiasuNewbie
**Posts:**3**Joined:**Fri Dec 05,

### Re: Q&A - PSLE Math

taringal wrote:Hi,

Can someone help on the following questions with clear explanation? Thank you.

Q1) May, Susan, Ben and Joey, each have some stickers. May has 50% as many stickers as the total number of stickers that Susan, Ben and Joey have. The number of stickers that Susan has is 25% of the total number of stickers that May, Ben and Joey has. The number of stickers that Ben has is 2/3 of the total number of stickers that May, Susan and Joey has. If May gives 20 stickers to Susan, May and Susan will then have an equal number of stickers. Find the average number of stickers each of them has.

Q2) In a donation drive, Ali, Hendri, Danny and Kaviin collected an average of $128. Ali collection 1/7 of the total amount collected by Hendri, Danny and Kaviin. Hendri collected 2/5 of the total amount collected by Danny and Kaviin. Danny collected 1/3 as much donations as Kaviin. How much donations did Ali collect?

Q3) A wallet contained some 2-dollar and 5-dollar notes in the ratio of 8:3. When 15 2-dollar notes were taken out and replaced with some 5-dollar notes, there was 16% less 5-dollar notes than 2-dollar notes. The total value of all the notes remained the same. What is the total value of all the notes in the wallet?

Hope this helps.

Q1 and Q2 are similar.

Q3 is abit odd. I know exactly how to solve, but i suspect some numbers aren't correct.