Q&A - P3 Math

[Taurus]

[Mod's note: threads merged]

Hi,

Anyone can help to explain how to get the answer:

Qns : When A is divided by 5, it gives a remainder. Which is the most possible pair of quotient (Q) and remainder (R) when A is divided by 5?

(1) Q = 5, R= 9
(2) Q = 6, R = 6
(3) Q = 5, R = 5
(4) Q = 6, R = 4

[BigDevil]

Hi, instead of starting a new thread for your question, please go to the http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=66&t=149 thread and post a reply there.


For this question, the answer is (4). In division, the remainder can never be equal or more than the divisor.

[e.011054chua]

Pls help me on this question.


In a class of 42 pupils, each boy received 3 stickers and each girl received 4 stickers from their teacher. Altogether the teacher gave out 154 stickers. How many girls were there in this class?

The answer is :
42 x 4 = 168
168-42 = 126
154-126 = 28

But I do not understand why 168-42 ?

[MathIzzzFun]

e.chua:

Pls help me on this question.


In a class of 42 pupils, each boy received 3 stickers and each girl received 4 stickers from their teacher. Altogether the teacher gave out 154 stickers. How many girls were there in this class?

The answer is :
42 x 4 = 168
168-42 = 126
154-126 = 28

But I do not understand why 168-42 ?

Hi
I think the answer provided is based on assumptive method... with 1 extra step.
Assume all are girls --> 3 x 42 = 126 (which is = 168 - 42)

The assumptive method can also be represented in form of area model ..

http://i43.tinypic.com/35a7ivo.png\">

cheers.

[Michaelia0816]

I also got a method, similar but more understanding!

Method: Assuming
Let us assume that all are boys
Time- 42x3=126
Minus- 154-126=28
Minus- 4-3=1
Divide- 28 divide 1=28
So the answer is 28.
remember TMMD method using assuming!

[peapot]

Oh! this method is abit like the 2 legs and 4 legs question.


I also have a question which I remember someone ask before. But I can’t understand why? Hope someone can explain.

Jeremy brought a sum of money to buy some pencils. If he buys 4 pencils, he would be left with $2. If he buys 5 pencils, he would need another $1.

How much is the cost of 1 pencil? and how much money did he have at first?

[mrswongtuition]

Hope this helps!


http://i43.tinypic.com/33tj7md.jpg\">

[peapot]

Thanks!

[Bunbun]

Hi there, need some help here:


Which of the following numbers can be a remainder when divided by 6 ?

(1) 8
(2) 7
(3) 6
(4) 4

I think it’s (4) but I am not sure.
Thanks in advance!

[mrswongtuition]

Bunbun:

Hi there, need some help here:


Which of the following numbers can be a remainder when divided by 6 ?

(1) 8
(2) 7
(3) 6
(4) 4

I think it's (4) but I am not sure.
Thanks in advance!

Rule to remember: The remainder must always be smaller than the divisor.
Therefore, all options which are the same as the divisor (6) or larger than the divisor (7 and are not possible.
The answer is 4.