Q&A - PSLE Math

[corneyAmber]

Tianzhu, I am adding the digits of the odd numbers, not the odd numbers.

The first series are single digit numbers which is equal to the odd numbers so you have mistaken that I am adding the odd numbers.

[corneyAmber]

1) Mr Mohn bought a certain number of cameras and watches for $1980.

Each camera cost $60. Each watch cost 1/4 as much as a camera.
If 40% of the items he bought were cameras, how many watches
did he buy?

Camera = $60
watch = $60/4 =$15

4Unit(60) + 6unit(15) = 1980

240u + 90u = 1980

u = 6

total watches = 6 * 6 =36

[tianzhu]

Hi ksi


Thank you for your clarification.

Best wishes

[tianzhu]

Brenda10:

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

[corneyAmber]

(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.

[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

[liketoeat]

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.

I agree with u. Ans should be $80.

[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.