Q&A - P5 Math

[mummyv]

tianzhu:

mummyv:

2. There are 9 stack of chairs. There are 12 chairs in each stack. Mohan places each chair equally spaced apart to for a perimeter of a rectangle. If the number of chairs places along the length is thrice the number of chairs placed along the breadth, how many chairs are placed along one of the lenghts of the rectangle. (Ans 42)

Hi

Good Morning.

Perhaps, for questions of such genre, it’s useful to have a simple pictorial representation. It might help to organise your thoughts.

Hope this helps.

Best wishes

http://farm6.staticflickr.com/5272/6897367566_8d8cd99d93_z.jpg\">

Thanks tianzhu. I hope I can reach your level sometime this year

[Zack7]

mathnoobs:

Zack7:

* i have to say these questions are quite tricky, harder than the questions i see at the p6 section

yes, pity our poor children.... so little time for play now....it's just mug, mug, mug...

problems of a country that strives too hard for excellence

[YumYum]

Hi, can anyone pls help with this Qn:


Kate baked some chocolate, oatmeal, and sultana cookies.

The ratio of the number of chocolate cookies to the number of oatmeal cookies to the number of sultana cookies is 12:7:10.

She wanted to pack some cookies in a box for her neighbor.

If she packed only the chocolate and oatmeal cookies in the box, she would have 20 such cookies left.

If she packed only the oatmeal and sultana cookies in the box, she would have 12 such cookies left.

A) how many cookies could the box contain?
B) how many cookies did she bake?

Thanks!

[YumYum]

Hi, I need help with this Qn:


2/9 of the students in a school scored an ‘A’ for a test.

The number of students who scored a ‘B’ was 1 2/3 (one and two thirds) the number of students who scored an ‘A’.

The rest of the students scored a ‘C’ and a ‘D’ in the ratio 6:5.

The number of students who scored an ‘A’ was 100 fewer than the number of students who scored a ‘B’.

A) how many students were there in the school?
B) how many more students scored a ‘B’ than a ‘D’?

Thanks!

[tianzhu]

YumYum:

Hi, can anyone pls help with this Qn:


Kate baked some chocolate, oatmeal, and sultana cookies.

The ratio of the number of chocolate cookies to the number of oatmeal cookies to the number of sultana cookies is 12:7:10.

She wanted to pack some cookies in a box for her neighbor.

If she packed only the chocolate and oatmeal cookies in the box, she would have 20 such cookies left.

If she packed only the oatmeal and sultana cookies in the box, she would have 12 such cookies left.

A) how many cookies could the box contain?
B) how many cookies did she bake?

Thanks!

Hi

chocolate cookies: oatmeal cookies: sultana cookies ----- 12:7:10.

12units + 7 units – 20

7 units + 10 units – 12

19 units – 20 = 17 units – 12
2 units = 8
1 unit = 4

The box can contain (17*4) – 12 or 56 cookies

Number of cookies ------- 29*4 -------116

You may also use Systematic Listing as an alternate way.

Best wishes

[tianzhu]

YumYum:

Hi, I need help with this Qn:


2/9 of the students in a school scored an 'A' for a test.

The number of students who scored a 'B' was 1 2/3 (one and two thirds) the number of students who scored an 'A'.

The rest of the students scored a 'C' and a 'D' in the ratio 6:5.

The number of students who scored an 'A' was 100 fewer than the number of students who scored a 'B'.

A) how many students were there in the school?
B) how many more students scored a 'B' than a 'D'?

Thanks!

Hi

You may use MD or work using units.

Use equivalent ratios to change 2/9 to 6/27 so as to make the calculations neater.

Students with A ----- 6 units
Students with B ------ 10 units
Students with C ------ 6 units
Students with D ------ 5 units

The number of students who scored an 'A' was 100 fewer than the number of students who scored a 'B'.

10-6 = 4

4 units = 100
1 unit = 25

Number of students = 27*25 = 675

5*25 = 125

125 more students scored a 'B' than a 'D'

Best wishes

[YumYum]

Hi Tianzhu,


Thank you for your help.

[mummyv]

Hi, pls help w this qn

John had 993 tables and chairs at first. After he sold 2/5 of the tables and 5/8 of the chairs, he had 459 tables and chairs left. How many tables did he sell? :slapshead: thanks for the help

[tianzhu]

YumYum:

Hi Tianzhu,


Thank you for your help.

Hi YumYum

Good Morning.

You're welcome.

Just curious, where are your two questions from?

Best wishes

[tianzhu]

mummyv:

Hi, pls help w this qn

John had 993 tables and chairs at first. After he sold 2/5 of the tables and 5/8 of the chairs, he had 459 tables and chairs left. How many tables did he sell? :slapshead: thanks for the help

Hi

Good Morning.

This question touches on simultaneous concepts.

If a student is familiar with SE, he/she may use it.

If not, he/she may solve the two equations pictorially,use the “Alphabet Method” or represent the variables with \"Units and Parts\"

Tables sold ------ TT
Tables left ------ TTT

Chairs sold ------ CCCCC
Chairs left ------ CCC

TTT + CCC ------- 459, hence T+C ------- 153

TT + CCCCC ----- 534 (993 – 459), therefore C -------- 76

T ------- 153 – 76 ------ 77

Tables sold ------- 2*77 ------- 154.

Best wishes