Yr 4

[alpine leaf]

Question 3 and 4

I would like an explanation what wtf question 3 and 4 means.

For question 4, I understand the idea, but I’m lost in the working out.

[glossy tulip]

3 and 4 numbering are not visible

[alpine leaf]

the two questions there

[glossy tulip]

Grandchildren one and the rectangle paper one these are 3 and 4 right?

[alpine leaf]

Yes

[glossy tulip]

Ok let's start with 3 first

Let's see the 2nd part
i have as many sons and daughters together as one eighth of my age

number of sons = x
Number of daughters= y 
Her age = 88
So
x+y = 1/8×(88)
x+y = 11```

Is this part clear?

[alpine leaf]

yupp

[glossy tulip]

Now first part
I have half as many grandchildren as I have daughter
And
Three fifth as many as I have sons

So we can write

Number of grandchildren=3/5(no of sons)=3x/5```

[alpine leaf]

okyup

[glossy tulip]

So we can write y/2 = 3x/5
Because both are same and denote no of grandchildren

So
y = 6x/5

[alpine leaf]

okie

[glossy tulip]

Substitute y=6x/5 in this equation

[alpine leaf]

x + 6x/5 = 11

5x +6x = 55
11x = 55
x = 5

[glossy tulip]

Yep , x was no of sons

What was number of grandchildren in terms of x?

[glossy tulip]

See this

[alpine leaf]

3 x 5/5
15/5
3

[glossy tulip]

Yup

That's the answer

[alpine leaf]

Wait, why arent we substitutin the other equation?

[glossy tulip]

What other equation?

[alpine leaf]

Wait jokes we just simplified it

So we can sub 5 into any of the son and daughter equaton

[glossy tulip]

5 is no of sons that is x

No of daughters is y, we did not find that because it's not require
But as x+y = 11
You can find y = 6

[alpine leaf]

aHH YTEAH That makes sense

ID HAVE to write it liek this for the kid

okk

cooliesss

Lets do the next one

[glossy tulip]

Unfortunately my work will start now so I have to go, do helpers ping and someone will assist you

[alpine leaf]

Ok1! NO worries. Thank you aso much for the help :))

[glossy tulip]

@alpine leaf You there ?.

[alpine leaf]

yES

[alpine leaf]

HGELO

[glossy tulip]

Let's do 2nd one
area of small rectangle is 1/5 of that of original paper

Width of original paper=15

So area = 15×20

Area of small rectangle= 1/5(area of original)
1/5×(15×20) = 60```

Clear till this point?

[alpine leaf]

Yup easy

[glossy tulip]

Now for area to be 60 , you need to find all pairs of length and breadth such that length×breadth = 60

[alpine leaf]

yupp

[glossy tulip]

So pairs are
(1,60) (2,30) (3,20) (4,15) (5,12) (6,10)

[alpine leaf]

Yep

[glossy tulip]

Now as we know the smaller rectangle is made of the bigger paper , it's length and breadth can either be equal to bigger paper or less, but can't be greater than either length or breadth
Understood?

[alpine leaf]

Yehh

[glossy tulip]

Now we are left with these 4 (3,20) (4,15) (5,12) (6,10)```

[alpine leaf]

okay

[glossy tulip]

Now you gotta visualise a bit because as a teacher I need a blackboard or whiteboard, but try to understand

[alpine leaf]

I think what's confusing is how do you know that 3x20 and 4x15 can fit 5 innit

[glossy tulip]

Let's take the first pair (3,20), see the length is same as the original rectangle paper
So we can take how many small rectangle

(3,20)
(3,20)
(3,20)
(3,20)```

[alpine leaf]

jokes

I do know

[glossy tulip]

These will be stacked like

=====
=====
=====
=====```

[alpine leaf]

300/60=5

5 x 12 and 6 x10 is cofusing actually

[glossy tulip]

No, that's for all small rectangle because all of them has area of 60

[alpine leaf]

Yeah

so 5 smaller ones can fit in the rectangle

[glossy tulip]

Yes but we need to find the pairs for which 4 of them can fit and 1 more can be of different size we don't care

Let me find a paper , maybe you will understand better that way

[alpine leaf]

Wait Yes it makes sense

so thats why they chose 5 x 12 and 6 x10 because ther would be 4 full squares that can fit and the leftovers

[glossy tulip]

Yessssss

4 size of same dimensions and leftover

[alpine leaf]

the 3x20

[glossy tulip]

For 3,20 and 4,15 it's 5 of same dimensions

[alpine leaf]

Where does it come from

[glossy tulip]

Our question restrict only 4 of same dimensions

[alpine leaf]

60x4=240 reminder 60

Ok i got it

im just stupid hhahahaa

[glossy tulip]

Try to draw the smaller rectangle one upon another

You will be able to visualise Better

[alpine leaf]

Ayee truee

Thank you bud