Brownbear:

pokemon97:

Anyone, pls help using model if possible:


A group of boys and girls are split into 3 classes, 5A, 5B and 5C. The number of pupils in each class is the same. The number of boys in 5A is equal to the number of girls in 5B. 1/5 of the boys are in 5C. If there are 160 more girls than boys.
(a) find the toal number of girls
(b) how many pupils are there altogether?

My understanding as follows but not sure if my working is purely model. Hope it is correct.

Assume total number of boys be 5u, then girls will be 5u+160

Class.......Boys.....Girls
5A & 5B.....4u.....4u
5C ...........u.......u + 160
------------------------------------------------
Total--------5u-----5u + 160

Since each class has same students and number of boys in 5A = number of girls in 5B, it implies number of girls in 5A = number of boys in 5B.

number of students in 5C is 1/3 of total number of students,

u+u+160 = 1/3 (5u+5u+160)
u = 80

a) total number of girls 5u+160 =560
b) total number of students 10u+160 = 960

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wanting05:

Please help me


An adult ticket to an amusement park costs $18 more than a child ticket. The adult ticket cost less than $25. A tour agency bought 4 times as many adult tickets as child tickets. It paid $3960 more for the adult tickets than child tickets. How many tickets did the tour agency buy?

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peggy:

tianzhu:

[quote=\"peggy\"]
Abigail and Benson had some money each. Abigail gave half of the amount she had to Benson. Benson then gave half of the amount he had to Abigail. In the end, Abigail had $224 and Benson had $98.
How much did each of them have at first ?

Hi peggy

Good Afternoon.

You may use “Working Backwards”.

For presentation purpose, you may use a tabulated format.

Abigail : Benson

224 : 98 (322) ----- In the end

126:196 (322)

252 :70 (322) ----- At first

Note -----1) Before Benson then gave half of the amount he had to Abigail, he had 98*2 ----- 196

2) Before Abigail gave half of the amount she had to Benson, she had 126*2 ----- 252

3) Total amount remains the same at 322.

Hope this helps.

Best wishes

Hi Tianzhu,

Is there any model presentation for such kind of question ?

Peggy[/quote]
Hope this model helps.
Since it is about shifting money between Abigail and Benson, the total remains unchanged.
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ectanz:

Hi, can anyone help me with the following question? TIA


Joyce and Nicole went shopping with the same amount of money. Joyce spent 4 times as much as Nicole. The amount of money Nicole had left was $90 more than the amount Joyce had left.
a. How much money did Joyce spend?
b. Nicole had $200 left. How much money did Nicole have at first?

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Miss Rumphius:

Please help for this question:


James and Bernard each had some sweets. If James gave Bernard 128 sweets, James would have 224 sweets more than Bernard. How many sweets must James give to Bernard so that Bernard would have 50 sweets more than James?

Our working:
224 + 128 + 128 = 480
James have 480 sweets more than Bernard.

How do we proceed from here?

The answer was provided but do not understand why is it done this way.

Thanks in advance!

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Here's another explanation.


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alng:

Hi,


This is Q39 from NYPS 2013 SA2:

In a farm, there are 20 chickens and cows.
All the cows have 2 more legs than all the chickens.
How many chickens are there?

The answer given is 13 chickens

Please advise how to solve this qn? Is there any missing information on the total no of legs? TIA!

I will use guess-and-check. Start with 10 cows and 10 chickens, and then 9 cows and 11 chickens, etc.

ssky2307:

Hi all

anyone has the solution to this?

Tricia gave 5 sweets to each of her friends and had 3 left. If Tricia had given 6 sweets each, she would be short of 4. How many sweets does Tricia have?

Algebraic solution is not accepted as this is a P3 question

Here's an alternate approach:
In the 1st Case of distributing 5 sweets, we can think of the Last Friend as ending up with 5 sweets plus 3 excess sweets = 8 sweets.
In the 2nd Case of distributing 6 sweets, we can think of the Last Friend as ending up with 2 sweets (short of 4 sweets).
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The number of friends and total sweets remains unchanged in both cases.

To find out the number of friends, we can redistribute the 8 sweets in the 1st Case such that it matches the 2nd Case.

We can only redistribute 6 sweets from the Last Friend, 1 each, to 6 other Friends in Case 1 for it to turn into Case 2. This means there are total of 7 friends.

Total sweets = 6 x 5 sweets + 8 sweets = 38 sweets

Kastro:

Natalie collected 28 postcards and Miranda collected 22 postcards. After Natalie gave Miranda some postcards, they had the same number of postcards. How many postcards did Natalie give Miranda?


Please help, thank you.

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Daddy

Pls advise on workings/steps for 3 questions below.

Not sure how to explain.
Thanks in advance.

3. Jim has twice as many bicycles as tricycles. The total number of wheels is 182.
a) How many tricycles does Jim have?
b) How many bicycles does Jim have?

Ans: 26 tricycles and 52 bicycles

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