Q&A - P5 Math

[tianzhu]

redruby:

At a concert, the ratio of the number of women to the number of men is 3:1. The ratio of the number of women to the number of children is 1:4. What is the ratio of the adults to the number of children at the concert?

Hi

You may use MD or work using units.

Women: Men ----- 3:1

Women: Children ----- 1:4 -------3:12

The ratio for women is repeated in both set of ratios, so make it the same.

Adult: Children ----- 4:12 -------1:3

Best wishes

[tianzhu]

elisammom:

Hi another question pls help


There are 4 times as many red pens as blue pens. 415 red pens and 46 blue pens were removed. As a result, the number of blue pens is 3 times as many as red pens. How many blue pens were there at first?
Tia

Hi

You may use Units and Parts.

At first
Red: Blue ------ 4u:1u

Change
Red: Blue ------ -415:-46

In the end
Red: Blue ------ 1p:3p

4u – 415 ----- 1p
(x3)
12u – 1245 ----- 3p

1u – 46 ----- 3p

Make the parts the same

12u – 1245 ------ 1u – 46

11u ------- 1199

1u ------ 109

Number of blue pens at first ------ 1u ------ 109

Best wishes

[elisammom]

smartmummy:

elisammom:

Hi pls help


Alice is 7 yrs old n her mother is 33 yrs old. How many years later will her mother be 3 times as old as Alice?
Tia

m [][][]
a []
2u=33-7=26 {age difference}
3u=13*3=39
6 years later

Thanks.
But why 13*3?

[cimman]

elisammom:

Hi another question pls help


There are 4 times as many red pens as blue pens. 415 red pens and 46 blue pens were removed. As a result, the number of blue pens is 3 times as many as red pens. How many blue pens were there at first?
Tia

here's an alternative solution, if you're comfortable with simultaneous equations:
http://i49.tinypic.com/fjn81x.png\">

if not, you can try this variation:
http://i50.tinypic.com/e9giva.png\">

as you can see, it is just a variation of the same basic equations. When the values are tabulated, it is much easier to see all the possible relationships in the problem. If the total values for Pens are given, then that adds another dimension to the relationship. The table enables one to see 2 dimensional relationships ie. relationships concerning total Pens, and relationships concerning individual Red and Blue Pens.

In more complex problem sums, you will have 3 dimensional relationships:
There were 1000 students at the parade ground and indoor sports hall. 40% of the 600 students at the parade ground were girls. 60% of the students at the indoor sports hall were girls. After some students in both venues moved from one venue to the other, 30% of the students in the parade ground and 70% of the students at the indoor sports hall were girls. How many students were there in the indoor sports hall after the movement had taken place ? Ans: 450
when relationships are structured that you have the diagram below, and you have values linking the different layers, then it is a 3 dimensional problem.
http://i47.tinypic.com/n3126t.png\">
The table concept can be extended easily to support multi dimensional problems. If you're interested in finding out more about Table Heuristics, check out the workshops here: http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=43&t=32278&start=190 , and drop me a PM.

[elisammom]

Thanks;)

[smartmummy]

elisammom:

smartmummy:

[quote=\"elisammom\"]Hi pls help


Alice is 7 yrs old n her mother is 33 yrs old. How many years later will her mother be 3 times as old as Alice?
Tia

m [][][]
a []
2u=33-7=26 {age difference}
3u=13*3=39
6 years later

Thanks.
But why 13*3?[/quote]1u=13

[tianzhu]

Jamesbond:

So is the answer 900? pl let me know. :nailbite:

Hi

Good Morning.

Would you like to share how did you get 900?

Best wishes

[Jamesbond]

tianzhu:

Jamesbond:

So is the answer 900? pl let me know. :nailbite:

Hi

Good Morning.

Would you like to share how did you get 900?

Best wishes

Am totally lost now...Broke my head for abt 30 mins.....not able to solve...Pl enlighten me... :rotflmao:

[Jamesbond]

tianzhu:

redruby:

At a concert, the ratio of the number of women to the number of men is 3:1. The ratio of the number of women to the number of children is 1:4. What is the ratio of the adults to the number of children at the concert?

[redruby]

tianzhu:

redruby:

At a concert, the ratio of the number of women to the number of men is 3:1. The ratio of the number of women to the number of children is 1:4. What is the ratio of the adults to the number of children at the concert?

Hi

You may use MD or work using units.

Women: Men ----- 3:1

Women: Children ----- 1:4 -------3:12

The ratio for women is repeated in both set of ratios, so make it the same.

Adult: Children ----- 4:12 -------1:3

Best wishes

Thanks for your help.