Q&A - P5 Math

[concerned1970]

Hi mathfreak, tysm for yr help. Btw, I dun get it why was that has to add 3 to 60 to get 63 for ques 2??


Someone pls kindly help me solve this pb sum.

For every bottle of perfume sold, Jessie gets $13. She also gets an extra $15 for every 9 bottles sold. How much money will she get if she sells 100 bottles of perfume?

[tianzhu]

concerned1970:

Hi mathfreak, tysm for yr help. Btw, I dun get it why was that has to add 3 to 60 to get 63 for ques 2??


Someone pls kindly help me solve this pb sum.

For every bottle of perfume sold, Jessie gets $13. She also gets an extra $15 for every 9 bottles sold. How much money will she get if she sells 100 bottles of perfume?

Hi

One way to do it is to use the Grouping Concept.

1 bottle of perfume ------- 13
9 bottle of perfume ------- 13*9 ------- 117

She also gets an extra $15 for every 9 bottles sold.

For every group of 9 bottles of perfume, she’ll get 132 (117+15)

100 ------99 + 1

There are 11 groups of 9 bottles of perfume.

(11*132) -------1452
1452+13 ------ 1465 (amount for selling 100 bottles of perfume)

Best wishes

[tianzhu]

concerned1970:

May I know how to copy and paste the text from the top sch paper online? I tried but didn't work, is there any other method cos it's quite troublesome to type everything out.

Hi

If you want to ask a question from past years papers (available online), you can list down the question number and provide a link to the test paper. It saves you the time for typing.

For example, Nan Hua CA1 Paper 2 P6 2011,Q7, please go to page 13 of this link.

http://www.orlesson.org/orp/11Ma/2011-P6-Math-CA1-NanHua.pdf

Best wishes

[concerned1970]

Tysm Tianzhu!


Btw, can u solve this ques for me? Cos my kids and I still dun get it. The method given by mathfreak was too profound for us to comprehend.

1) Kanxi is 5 times as old as Jaycee this year. Jaycee is 9 years old now. In how many years' time will Kanxi's age be twice that of Jaycee?

[mathfreak]

concerned1970:

Hi mathfreak, tysm for yr help. Btw, I dun get it why was that has to add 3 to 60 to get 63 for ques 2??


Someone pls kindly help me solve this pb sum.

For every bottle of perfume sold, Jessie gets $13. She also gets an extra $15 for every 9 bottles sold. How much money will she get if she sells 100 bottles of perfume?

If a number leaves a remainder of 3 when divided by n, it means that it is 3 more than a certain multiple of n. For example, 33 leaves a remainder of 3 when divided by 10, and it is 3 more than the third multiple of 10 (30). So we added 3 to the lowest common multiple of 12 and 15 to get the lowest number that leaves a remainder of 3 when divided by 12 and 15.

[tianzhu]

concerned1970:

Tysm Tianzhu!


Btw, can u solve this ques for me?

Hi

Kanxi is 5 times as old as Jaycee this year. Jaycee is 9 years old now.

Jaycee ------- 9
Kanxi ------- 45
Difference in age --------36

The age’s difference between two people always remains the same.

For Kanxi's age be twice that of Jaycee, Kanxi will be 72 years old and Jaycee will be 36 years old.

36 – 9 ------ 27

So the answer is in 27 years time.

Best wishes

[concerned1970]

Ty tianzhu! Now my kids have clearer picture of the explanation.


Thanks too, math freak!

[savoury sweet]

Hi


My gal had some problem in solving the two questions as below. Can anyone help?

1)Tap A can fll up a tank in 4 minutes. Tap B can fill up the same tank in 6 minutes.
How long will it take to fill up the tank if both taps are turn on at the same time?
(Ans: 2mins 24 secs)

2)When a bucket is 1/7 filled with water, its mass is 5 kg. The mass of the bucket is
25 kg when water is filled to the brim. What is the mass of the empty bucket?
(Ans: 2 kg)

Thanks so much.

[tianzhu]

savoury sweet:

Hi


My gal had some problem in solving the two questions as below. Can anyone help?

1)Tap A can fll up a tank in 4 minutes. Tap B can fill up the same tank in 6 minutes.
How long will it take to fill up the tank if both taps are turn on at the same time?
(Ans: 2mins 24 secs)

2)When a bucket is 1/7 filled with water, its mass is 5 kg. The mass of the bucket is
25 kg when water is filled to the brim. What is the mass of the empty bucket?
(Ans: 2 kg)

Thanks so much.

Hi

(1) A common multiple of 4 and 6 is 12.

Tap A
4 mins ------ 12 units
1 min ------ 3 units

Tap B
6 mins ------ 12 units
1 min ------ 2 units

In 1 min, tap A and tap B ------- 5 units

12 units ------ 10 units + 2 units

10 units ------ 2 min
2 units -------- 2/5*60 ------ 24 seconds

Total time ------ 2 mins 24 seconds.

(2) Is the number 23kg or 25kg?

Best wishes

[savoury sweet]

tianzhu:

savoury sweet:

Hi


My gal had some problem in solving the two questions as below. Can anyone help?

1)Tap A can fll up a tank in 4 minutes. Tap B can fill up the same tank in 6 minutes.
How long will it take to fill up the tank if both taps are turn on at the same time?
(Ans: 2mins 24 secs)

2)When a bucket is 1/7 filled with water, its mass is 5 kg. The mass of the bucket is
25 kg when water is filled to the brim. What is the mass of the empty bucket?
(Ans: 2 kg)

Thanks so much.

Hi

(1) A common multiple of 4 and 6 is 12.

Tap A
4 mins ------ 12 units
1 min ------ 3 units

Tap B
6 mins ------ 12 units
1 min ------ 2 units

In 1 min, tap A and tap B ------- 5 units

12 units ------ 10 units + 2 units

10 units ------ 2 min
2 units -------- 2/5*60 ------ 24 seconds

Total time ------ 2 mins 24 seconds.

(2) Is the number 23kg or 25kg?

Best wishes

Hi Tianzhu,

Thanks for your help. With regards to the 25 or 23kg, I have no idea,my gal copied down from the computer as part of the school home based learning today. She can't view the question again once submitted. She got both of the questions wrong.

If you dont mind, can you show me the work out of the qns? :oops:
Thanks a lot Tianzhu.