Q&A - PSLE Math

[Brenda10]

tianzhu:

Brenda10:

[quote=\"sexymama\"]I've been struggling

with my DD h'wk....Pls help..


(2) $400 were shared by 4 boys. Alan received 25% of the total amount
that Ben, Carl and Dan received. Ben's share was 60% of the
amount received by Carl and Dan. Carl received 4 times as much
as Dan. How much more did Ben receive than Dan?

Give a try :? and hope someone else may has a better method and also help to confirm is the answer correct.

Alan recd 25% of the ttl that (B,C & D recd) : $400 x 1/4 = $100
Bal for B, C & D - $400 - 100 = $300
Ben recd 60% of Carl and Dan = $300 x 60% = $180
Bal for Carl and Dan - $300- $180 = $120
Carl recd 4 times as much as Dan - $120 / 5 = $24
$180 - $24 = $156

Answer: Ben recd $156 more than Dan

Thank you.

Hi Brenda10

You may want to take another look at this

Alan recd 25% of the ttl that (B,C & D recd) : $400 x 1/4 = $100

Best wishes[/quote]Hi Tianzhu

Thank you for your highlight.

I am not good in ratio and will let DD try tonight see whether she is able to solve.

Thank you and have a nice day.

[Brenda10]

Brenda10:

tianzhu:

[quote=\"Brenda10\"]
Give a try :? and hope someone else may has a better method and also help to confirm is the answer correct.

Alan recd 25% of the ttl that (B,C & D recd) : $400 x 1/4 = $100
Bal for B, C & D - $400 - 100 = $300
Ben recd 60% of Carl and Dan = $300 x 60% = $180
Bal for Carl and Dan - $300- $180 = $120
Carl recd 4 times as much as Dan - $120 / 5 = $24
$180 - $24 = $156

Answer: Ben recd $156 more than Dan

Thank you.

Hi Brenda10

You may want to take another look at this

Alan recd 25% of the ttl that (B,C & D recd) : $400 x 1/4 = $100

Best wishes

Hi Tianzhu

Thank you for your highlight.

I am not good in ratio and will let DD try tonight see whether she is able to solve.

Thank you and have a nice day.[/quote]Hi Tianzhu

I'm happy dd able is able to work out this question by using ratio. She said this question was similar to the one she had did before :


Four girls. E, F, G and H shared $480. E received 1/2 of the total amount of money received by F, G and H. F recieved 2/3 of the total amount received by G and H. H received 1/3 as much money as G.
Need to find how much money did H recd and what fraction of E's money is H's money if E gave $40 to H ?

Thank you. :lol:

[corneyAmber]

Brenda10:

ksi:

(2) $400 were shared by 4 boys. Alan received 25% of the total amount

that Ben, Carl and Dan received. Ben's share was 60% of the
amount received by Carl and Dan. Carl received 4 times as much
as Dan. How much more did Ben receive than Dan?

Dan = u
Carl = 4u
Dan + Carl = 5u
Ben = 0.6(5u) = 3u
dan +Carl + ben = 8u
Alan = 0.25(8u) = 2u

ben is 3u-u=2u more than dan.

10u = 400
2u = 80

hence ben is $80 more than dan.

Hi KSI

I think your answer is right and I like your method.

Thanks

Thanks Brenda, I was trying to do an imaginary model in my mind as I was using iphone to solve this earlier. Great that you can understand my steps without a diagram.

[tianzhu]

Brenda10:

Brenda10:

[quote=\"tianzhu\"]
Hi Brenda10

You may want to take another look at this

Alan recd 25% of the ttl that (B,C & D recd) : $400 x 1/4 = $100

Best wishes

Hi Tianzhu

Thank you for your highlight.

I am not good in ratio and will let DD try tonight see whether she is able to solve.

Thank you and have a nice day.

Hi Tianzhu

I'm happy dd able is able to work out this question by using ratio. She said this question was similar to the one she had did before :


Four girls. E, F, G and H shared $480. E received 1/2 of the total amount of money received by F, G and H. F recieved 2/3 of the total amount received by G and H. H received 1/3 as much money as G.
Need to find how much money did H recd and what fraction of E's money is H's money if E gave $40 to H ?

Thank you. :lol:[/quote]Hi Brenda10

Great.
Yes, these questions are similar.

Best wishes

[angela]

Can anyone help me with this?


Ali, Bala and Charles shared a tin of cookies. Ali took 5/6 of the tin of cookies and 1/3 of a cookie. Bala took 5/6 of the remaining tin of cookies and 1/3 of a cookie. Charles received only 2 cookies. How many more cookies did Ali have than Bala?

Thks

[MOE Hater]

angela:

Can anyone help me with this?


Ali, Bala and Charles shared a tin of cookies. Ali took 5/6 of the tin of cookies and 1/3 of a cookie. Bala took 5/6 of the remaining tin of cookies and 1/3 of a cookie. Charles received only 2 cookies. How many more cookies did Ali have than Bala?

Thks

Let cookies at first be x

x x 1/6 - 1/3 x 1/6 -1/3 = 2

1/6x - 1/3 x 1/6 = 2 1/3

1/6x - 1/3 = 14

1/6 x = 14 1/3

x = 86

Ali's cookies = 5/6 x 86 + 1/3
= 72

Bala's cookies = 86 - 72 - 2
= 12

Difference = 72 - 12
= 60

[Vanilla Cake]

angela:

Can anyone help me with this?

Sure and you may wish to help us back by telling where is the source of this question? Which school, assessment book, tuition centre etc?

angela:

Ali, Bala and Charles shared a tin of cookies. Ali took 5/6 of the tin of cookies and 1/3 of a cookie. Bala took 5/6 of the remaining tin of cookies and 1/3 of a cookie. Charles received only 2 cookies. How many more cookies did Ali have than Bala?

Working backwards concept
Bala+Charles= 5/6 of remaining tin of cookies+1/3 of a cookie+2 cookies (2 cookies for Charles)
5/6 of the remaining tin of of cookies -> Bala
1/6 of the remaining tin of cookies -> 1/3 of a cookie+2 cookies
(Next step is to multiply by 6 for the above statement only)
6/6 of the remaining tin of cookies = 2 cookies +12 cookies = 14 cookies
Number of cookies for Bala = (14-2)cookies = 12 cookies

Ali: 5/6 of the tin of cookies+1/3 of a cookie
Remainder for Ali = 1/6 of the tin of cookies+1/3 of a cookie +14 cookies
(14 cookies from Bala (12 cookies) and Charles (2 cookies)
1/6 of total cookies = 1/3 of a cookie+14 cookies
Multiply by 6
Total cookies = 2+84=86
Number of cookies for Ali = (86-14) cookies = 72 cookies

Difference in the cookies for Ali and Bala = 72-12 = 60
Ali had 60 more cookies than Bala.

Note: In actual exam, there is no need to write so many steps as shown above.The additional steps are written for explanation and can be omitted where appropriate.

Hope that other members can come forward with pictorial diagram to help you understand better.Otherwise, you may consider using algebra as shown by MOE Hater which is a fast and efficient way to solve this problem.

[corneyAmber]

Vanilla Cake:

Bala+Charles= 5/6 of remaining tin of cookies+1/3 of a cookie+2 cookies (2 cookies for Charles)

5/6 of the remaining tin of of cookies -> Bala
1/6 of the remaining tin of cookies -> 1/3 of a cookie+2 cookies
(Next step is to multiply by 6 for the above statement only)
6/6 of the remaining tin of cookies = 2 cookies +12 cookies = 14 cookies
Number of cookies for Bala = (14-2)cookies = 12 cookies

Hi VC,

I have a question for you:
If Bala -> 5 parts out of 6 of remaining tin of cookies,
after you get 6/6 of remaining tin of cookies = 14,
Shouldn't bala be 5/6 * 14 = 35/3 = 11 2/3 cookies instead of 12?

The final answer is not a round number but a fraction from my calculation.
Also, logically, if ali has 1/3, bala also 1/3 of a cookie, and charlie a whole number, the final answer should have a 1/3 somewhere to complete that cookie? Do we assume tins of cookies can be packed with fractions of cookies in total from a manufacturer? Just some food for thought or I am missing something here? Kindly enlighten.

[liketoeat]

Hi, I don’t know if this question is appropriate for P6 but my niece received it as her homework from her school teacher.


Toy Train A and Toy Train B are 15 m apart from each other. When the toy trains moved towards each other, they would meet in 5 min. However, if the toy trains moved in the same direction, toy Train A would overtake Toy Train B in 5/12 h. Find the speed of Toy Train A and Toy Train B.

[liketoeat]

Vanilla Cake:

angela:

Can anyone help me with this?

Sure and you may wish to help us back by telling where is the source of this question? Which school, assessment book, tuition centre etc?

Roysth 2009 P6 CA1 Paper 2 Q17