Q&A - P3 Math

[rrjan]

Thanks for your kind help KSMe, i think my boy will be able to understand your explaination as its very clear :celebrate:

[concernParent777]

Hi all,


I am stucked in a P4 Math question while helping out my son, any idea where I can post it? Thanks

[autumnbronze]

Hi,


:rahrah: :welcome: :welcome: :rahrah:

You may direct yourself to this link:

http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=149&start=650

[concernParent777]

Thanks, but I have taken a picture of the question, how do I upload the pic?

[tankee]

concernParent777:

Thanks, but I have taken a picture of the question, how do I upload the pic?

please see instructions here

http://www.kiasuparents.com/kiasu/forum/viewtopic.php?p=132258#132258

[Bunny27]

Hi Maths Guru,


Below are 2 questions which I needed help :

a) A,B and C shared some comics among them. A received 2/5 of them while B received 5/6 of what he and C received altogether. If A received 180 more comics than C, how many comics did B received?

b) A can of juice had a mass of 1100g when it was 1/4 full. Another identical can had a mass of 3200g when it was 5/6 full. What was the mass of each can when it was filled complete with juice?

[Pen88n]

Bunny27:

Hi Maths Guru,


Below are 2 questions which I needed help :

a) A,B and C shared some comics among them. A received 2/5 of them while B received 5/6 of what he and C received altogether. If A received 180 more comics than C, how many comics did B received?

b) A can of juice had a mass of 1100g when it was 1/4 full. Another identical can had a mass of 3200g when it was 5/6 full. What was the mass of each can when it was filled complete with juice?

a) Think of a model with 10 parts,
A = 2/5 = 4 parts
B = 5/6 of the remainder = 5 parts
c = 1/6 of the remainder - 1 part
So the model will looke like this: AAAABBBBBC

Diff between A and c = 3 parts = 180
1 part = 60
B has 5 parts = 60 x 5 = 300

b) Diff between 2 cans: 5/6 - 1/4 = 10/12 - 3/12 = 7/12
When can is filled with 7/12 juice, the juice (without the can) will weigh 3200g - 1100g = 2100g
1/12 can of juice (without can) will weigh 2100g/7 = 300g

3/12 can of juice with can weighs 1100g
Add another 9/12 juice to fill up the can, that will add in anther weight of 300g x 9 = 2700g
Total weight of can filled with juice = 2700g + 1100g = 3800g

[24hr-mum]

ben is an office boy who works in a building where every floor has a lift


his routine begins when he leaves his office and takes the lift 9 floors up to Mr Tan’s office. He then goes to Mrs Wong’'s office 5 floors below Mr Tan’s office to collect a parcel.
Next, he takes the lift 15 floors up to hand the parcel to Miss Lee. After that, he takes the lift 20 floors down back to the first floor. On which floor is Ben’s office located?


is the answer 1st or 2nd floor?
is Miss Lee on 20th floor, Mr Tan on 10th floor and Mrs Wong on 5th floor?

[mrswongtuition]

24hr-mum:

ben is an office boy who works in a building where every floor has a lift


his routine begins when he leaves his office and takes the lift 9 floors up to Mr Tan's office. He then goes to Mrs Wong''s office 5 floors below Mr Tan's office to collect a parcel.
Next, he takes the lift 15 floors up to hand the parcel to Miss Lee. After that, he takes the lift 20 floors down back to the first floor. On which floor is Ben's office located?


is the answer 1st or 2nd floor?
is Miss Lee on 20th floor, Mr Tan on 10th floor and Mrs Wong on 5th floor?

This is my interpretation:

Working backwards:
he takes the lift 20 floors down back to the first floor.
This means that he was on the 21st floor before he went back to the first floor. Miss Lee's office is on the 21st floor.

he takes the lift 15 floors up to hand the parcel to Miss Lee
This means that he was on the 6th floor. Mrs Wong's office is on the 6th floor.

He then goes to Mrs Wong''s office 5 floors below Mr Tan's office to collect a parcel.
This means that he was on the 11th floor. Mr Tan's office is on the 11th floor.

he leaves his office and takes the lift 9 floors up to Mr Tan's office.
This means that he was on the 2nd floor. His office is on the 2nd floor.

I was wondering about the first step and thinking, should it be 20th floor or 21st floor since the question says '20 floors back down'.

Then I thought: If I'm on the 2nd floor and I go 1 floor back down, I would be on the first floor.
Which means that if I'm on the 20th floor and I go 20 floors back down, I won't be at the 1st floor. I'll be at B1.

[24hr-mum]

this is a sch hmwk. the teacher’s answer is 2nd flr.

how to present the answer? draw a number line?