Q&A - P5 Math

[Trina]

MathIzzzFun:

Trina:

Please assist with this question:


There are 40 pupils in a class. Each boy donated $3 and each girl donated $2. The boys donated $30 more than the girls.
How many boys are there?
How many girls are there?

Thanks!

Assume all boys donated, total amount --> 40 x $3 = $120
$120 - $30 = $90 --- excess amount to be reduced by girls' donation
Number of girls = $90/($3+$2) = 18
Number of boys = 40-18 = 22

cheers.

Thanks but still dont get it.. Can provide narration? Thanks

[ttyh]

Luke had $140 and Issac had $92 at first. After they spent an equal amount of money, Luke had 4 times as much money as Isaac. How much did each of them spend?

(not sure if this has been asked before, pls refer me to correct page. Thanks!)

[php]

ttyh:

Luke had $140 and Issac had $92 at first. After they spent an equal amount of money, Luke had 4 times as much money as Isaac. How much did each of them spend?

(not sure if this has been asked before, pls refer me to correct page. Thanks!)

3 units -> $140 - $92 = $48
1 unit -> $48 / 3 = $16

$92 - $16 = $76

Each of them spent $76

[Trevortan]

If you need the whole answer key, I don't think I could help. But if you just need some answers from the answer key, then you can go to the website. http://www.onsponge.com/shop/online-solutions.html

Hope I helped

[Oracle]

Serene, Fabian and Eileen shared their prize money of $4100 among themselves. Twice of Serene’s share was equal to 5 times of Fabian’s share. 4 times of Serene’s share was also equal to 3 times of Eileen’s share. Calculate Serene’s share.


Help … please. How should the answers be presented and is this really a P5 appropriate question?

Thank you very much.

[speedmaths.012624com]

Oracle:

Serene, Fabian and Eileen shared their prize money of $4100 among themselves. Twice of Serene's share was equal to 5 times of Fabian's share. 4 times of Serene's share was also equal to 3 times of Eileen's share. Calculate Serene's share.


Help ...... please. How should the answers be presented and is this really a P5 appropriate question?

Thank you very much.

Hi Oracle,

One Possible Solution:

Twice of Serene's share was equal to 5 times of Fabian's share.
This means that ratio of Serene's share to Fabian's share is 5:2
(Just interchange the 2 numbers)

4 times of Serene's share was also equal to 3 times of Eileen's share.
This means that ratio of Serene's share to Eileen's share is 3:4
(Just interchange the 2 numbers)

Ratio of Serene's share to Fabian's share is 5:2
Ratio of Serene's share to Eileen's share is 3:4

Ratio of Serene's share to Fabian's share to Eileen's share is 15:6:20

15 + 6 + 20 = 41 units
41 units = $4100

Can you work from here?

Cheers


speedmaths.com

.

[MathIzzzFun]

Oracle:

Serene, Fabian and Eileen shared their prize money of $4100 among themselves. Twice of Serene's share was equal to 5 times of Fabian's share. 4 times of Serene's share was also equal to 3 times of Eileen's share. Calculate Serene's share.


Help ...... please. How should the answers be presented and is this really a P5 appropriate question?

Thank you very much.

http://i45.tinypic.com/s31vkw.png\">

cheers.

[MathIzzzFun]

Trina:

MathIzzzFun:

[quote=\"Trina\"]Please assist with this question:


There are 40 pupils in a class. Each boy donated $3 and each girl donated $2. The boys donated $30 more than the girls.
How many boys are there?
How many girls are there?

Thanks!

Assume all boys donated, total amount --> 40 x $3 = $120
$120 - $30 = $90 --- excess amount to be reduced by girls' donation
Number of girls = $90/($3+$2) = 18
Number of boys = 40-18 = 22

cheers.

Thanks but still dont get it.. Can provide narration? Thanks[/quote]http://i49.tinypic.com/29qd1g3.png\">

cheers.

[TheBluePapa]

this seems quite ingenious, but rather mind bending. Think I’ll stick to simultaneous equations.

[Oracle]

Yes Speedmath, I got it. Just have to put Serene on the same platform & everything becomes clear.


However this is a "whole number" question. Son hasn’t been taught ratio yet so perhaps got to use MathIzzzFun’s workings but I wonder how the common numerator 60 come about.

Could MathIzzzFun enlighten me please.

Thank you very much.