MathIzzzFun:

ChewingPencilLine:

[quote=\"carol73\"]ariel has a rectangle cardboard that measures 19cm by 15cm. she wants to cut out as many rectangular pieces as she can from it. each small rect piece measures 5cm by 3cm. what is the most number of small rect pieces she can get?

depending on how you orientate the rectangles, it can be

EITHER

19cm / 5cm = 3 R 4cm
15cm / 3cm = 5

number of small rectangular pieces obtained = 3 x 5 = 15

OR

19cm / 3cm = 6 R 1cm
15cm / 5cm = 3

number of small rectangular pieces obtained = 6 x 3 = 18

The latter obviously yields more rectangular pieces. Therefore, the maximum number of small rectangular pieces obtainable is hence 18.

http://i42.tinypic.com/13ykqhh.png\">

cheers.[/quote]Thanks for the correction. I did think of this but presumed that they will not be expected to do it this way... Since it is at primary level. Realized from experience that sometimes, this is not required in the answers for certain assessment books. I forgot this is primary 5, lol. Sorry for the error. This is absolutely valid.

carol73:

hi


pls help

There were 1408 chinese and malay story books in a library. When the librarian bought 73 chinese books and 59 malay books, there were as many chinese books as malay books in the library. how many malay books were there at first?

I think you are missing a word there... ?

However, a simple way to do it would be to calculate the total number of books in the end and work from there i.e.

1408 + 73 + 59 = 1540 books in the end

Assuming thrice as many Chinese books as Malay books in the end,
4 units: 1540
1 unit: 1540 / 4 = 385
Therefore, number of Malay books in the end is 385.
Number of Malay books at first = 385 - 59 = 326

ADD-ON [EDIT]:

HAHA, SO SORRY, OMG. I assumed that a word was missing out of reflex. I just realized that MathIzzFun is probably right in taking your question to mean what it actually does mean, ._. I have no idea why I did not accept the question as it was. Strange. Sorry!

carol73:

ariel has a rectangle cardboard that measures 19cm by 15cm. she wants to cut out as many rectangular pieces as she can from it. each small rect piece measures 5cm by 3cm. what is the most number of small rect pieces she can get?

depending on how you orientate the rectangles, it can be

EITHER

19cm / 5cm = 3 R 4cm
15cm / 3cm = 5

number of small rectangular pieces obtained = 3 x 5 = 15

OR

19cm / 3cm = 6 R 1cm
15cm / 5cm = 3

number of small rectangular pieces obtained = 6 x 3 = 18

The latter obviously yields more rectangular pieces. Therefore, the maximum number of small rectangular pieces obtainable is hence 18.

swordtail:

Sandra has twice as many apples as oranges at first. She removes 4 apples and 3 oranges each time. In the end, there are 18 apples and 1 orange left. What is the total number of fruits Sandra had at first?


Tianzhu,
tks for the solution. But could you draw the model drawing? Still a bit confused, like how do you get the 6 units? tks

tks for your solution

\"18 + 4 units ------ 2 parts

1 + 3 units ------ 1 part\"

you get 2 + 6 units by multiplying the second line by 2
i.e. 2 + 6 units ------ 2 parts

Therefore, 18 + 4 units = 2 + 6 units since both are equivalent to 2 parts.

doraemo:

Thank you, ChewingPencilLine!!!!!!!!!!

You're welcome Glad to be of help!

doraemo:

3)\tB had 400 sticks of chicken satay and mutton satay in all. After selling 1/9 of the chicken satay and 15 sticks of mutton satay, he had ¼ as many mutton satay as chicken satay left. How many sticks of chicken satay did B have at first?

How to draw the model?
1. Draw 4 units for chicken satay and 1 unit for mutton satay (this is for 'in the end')
2. The 4 units of chicken satay is after 1/9 of the original number of chicken satays was sold. 1 - 1/9 = 8/9. That means to say that 8 out of 9 of the original units are left. So, cut the 4 units into 8 parts (chop each unit into 2). Similarly, cut the 1 unit for the mutton satay into 2 parts.
3. Draw back the 15 mutton satays sold. Make sure that it's doesn't look like it's the same size as your units.
4. Tadah, you have the models for 'at first'.

Chicken satay: 9 units
Mutton satay: 2 units + 15
Total: 400

Therefore, 11 units: 400 - 15 = 385
1 unit = 385 / 11 = 35

Number of chicken satay at first = 35 x 9 = 315
Number of mutton satay at first = 35 x 2 + 15 = 85
OR just 400 - 315 = 85.

* very similar to question 2 *

doraemo:

Pls help. 3 questions:


1)\tA and B had an equal amount of money. Everyday, A spent $36 and B spent $48. When B had spent all his money, A had $240. How much money did each of them have at first?

2)\tD has $160 more than R. If D gives R 1/10 of his money, he will have 3 times as much money as Raja.
a)\tHow much money does R have at first
b)\tExpress R’s money as a fraction of D’s money?

1. Everyday, B spent $48 - $36 = $12 more than A.
Since they both started with the same amount of money, $240 / $12 = 20,
we know that the $240 more that A has at the end when B had spent all his money is accumulated over 20 days of 'savings'.
Therefore, 20 x $48 = $960
OR 20 x $36 + $240 = $960

They each have $960 at first.

2.
http://i36.tinypic.com/346nfib.png\">

Augmum:

tree nymph:

ChewingPencilLine,


Bravo!

Wow.....好久不见！！！

ChewingPencilLine,
\"Once a Dunmanian, always a Dunmanian\". :celebrate: (on behalf of my gal)

She is more than proud being a Dunmanian.....

YAYYYYY! Cheers to being a Dunmanian! Dunmanian for life indeed!

michdoughnuts:

' If you want tuition for SATs, you can actually approach me, :). '


haha so you do private tuitions? Any more details? Could you provide the subscription e-mail as well? Thanks!

Haha, yup, I am a private home tutor, :).
I teach quite a range of subjects:
Primary level English, Math, Science and Chinese (EMSC) as well lower secondary Math and upper secondary E/A-Math, Physics and Chemistry, JC H1 Economics, H1/2 Math, H1/2 Physics and SIM Business Math, Statistics and Accounting modules

And of course, I teach SAT too.

For the subscription, go here and click on the little blue word 'subscription' on the right beside 'print'.
http://sat.collegeboard.org/practice/answered-question-of-the-day

tianzhu:

veraclari:

HI SORRY shd be Jane's spending. . Fjanks for helping in e questions. . But girl asking me how to draw model too... really got me siah.. model me cannot. .. ha ha h

Hi

Good Morning.

There are alternative ways to present the MD.I've shown two options.

Hope your girl will find it useful.

Best wishes

http://farm9.staticflickr.com/8115/8607173179_2eb41f9ca3_z.jpg\">

Just going to point out that you are assuming that they spent everything they brought. You might think this a moot point but I was confounded when I first read this question, ._.

Cheers.