Help Please! (1 Viewer)

[manifestation]

Help with a few questions.

How the hell is the answer 8!?!?!

And why isn't the answer 35?

Thanks

- Mani

 

[freakinout]

ok for the first question...
the population increased by 20% so it went from 100% to 120%......
then it decreased by 10% of the 120... so 10% of 120 = 12%

therefore the population at the end of two year is 120% - 12% = 108%

now u can see it went from 100% to 108% therefore increased by 8


the second question ..

because it is cumalitive frequency (maning that they added the frequncies as they went along) so to find how many watch four movies you have to sibtract 35 by wutever number of movies was before that which in this case is 25 there fore its ten!

hope i helped any thing else?

 

[manifestation]

Another one

Thanks lovely!! Yes i need help with one more...it's so embarrassing, i keep asking for help, cause i'm doing the multiple choice on BOS...and a few are pretty confusing

 

[Muzzaw]

arc length = (theta/360) x 2 x pi x r

Therefore: theta = (arc length x 360) / (2 x pi x r)

= 69 degrees.

 

[freakinout]

using the circumfrance of a circle.. = pie x diamter
= pie x 20
= 62.831...

the arc lenth of the cirlce (12) is a part of that circumfrence... therefor if u find the percentage.... 12/62.831.. x 360 and then press the degrees minutes seconds button .... it wiil give the angle....

the reason that we times it by 360.. is because the total degrees of a cirlce is 360.

another way u can work it outs is to say well...

12/62.831 = x/360 and cross multiply

get it?

 

[manifestation]

Thanks...but no i don't get it. I don't get where all the 2 x pie x r^ ???

 

[sally_33]

the formula for that last one posted is on the formula sheet. if you see a question you can't do always check the formula sheet first before you freak out

edit: its the 'arc length of a circle' formula

 

[manifestation]

I know, but i don't how to get it so theta is what i'm solving for! I hate re - arranging formula's! And in the general course that's all you freakin' do!!!!!!!!!!!!!!!!!!!

 

[Muzzaw]

Ok

arc length = (theta/360) x 2 x pi x r

That is the same as saying: arc length = (theta x 2 x pi r)/360

So you take the 360 to the left: (arc length x 360) = theta x 2 x pi x r

Now you want to get rid of 2 x pi x r, so:

(arc length x 360) / (2 x pi x r) = theta.

I can't explain it any better, sorry.

 

[freakinout]

well yeh if ur gna use the formula on the sheet then u have to solve it to find theta but i hate doing thta too thats y i showed u the other way lol... um im not sure how else to explain it .. let me think about it...

 

[sally_33]

l = theta/360 x 2 x pi x r

you just substitute in the values you have

12cm = theta/360 x 2 x pi x 10

[work out what you can]

12 cm = theta/360 x 62.83

[then divide 12 by that number]

.19 = theta/360

[multiply both sides by 360]

68.4 = theta






(it may be either C or D because i rounded off too early but just follow those steps)

 

[manifestation]

I apologise for my slowness...

Ok

arc length = (theta/360) x 2 x pi x r

That is the same as saying: arc length = (theta x 2 x pi r)/360

So you take the 360 to the left: (arc length x 360) = theta x 2 x pi x r

Now you want to get rid of 2 x pi x r, so:

(arc length x 360) / (2 x pi x r) = theta.

I can't explain it any better, sorry.

No no, it's alright, I think my mind is following your explaination! Wohoo! But if they have a question like this i will die..*cries*

I have another one!!

I have done this question about 3 times and i still get it wrong!!

 

[manifestation]

l = theta/360 x 2 x pi x r

you just substitute in the values you have

12cm = theta/360 x 2 x pi x 10

[work out what you can]

12 cm = theta/360 x 62.83

[then divide 12 by that number]

.19 = theta/360

[multiply both sides by 360]

68.4 = theta






(it may be either C or D because i rounded off too early but just follow those steps)

Omg, that's really good too...jeez you guys are good! Thanks darls!

 

[Casmira]

sallys on fire with maths!

 

[freakinout]

No no, it's alright, I think my mind is following your explaination! Wohoo! But if they have a question like this i will die..*cries*

I have another one!!

I have done this question about 3 times and i still get it wrong!!

1m^2 = 80 grams

1m^2 = 0.08kg

now work out how many metres square in each sheet of paper
= 0.21m^2 x 0.3m^2
= 0.0623m^2

now find out how much each sheet weighs
= 0.063m^2 x 0.08 kg
= 0.00504kg per sheet

so find out how many sheets u divide the mass of the whole pile by the mas of one sheet which gives u 5000 sheets

 

[manifestation]

Awww, thanx you are a gem!

 

[Digital_Spork]

1m^2 = 80 grams

1m^2 = 0.08kg

now work out how many metres square in each sheet of paper
= 0.21m^2 x 0.3m^2
= 0.0623m^2

now find out how much each sheet weighs
= 0.063m^2 x 0.08 kg
= 0.00504kg per sheet

so find out how many sheets u divide the mass of the whole pile by the mas of one sheet which gives u 5000 sheets

why 0.21 ^2 by 0.3 ^2 ... and how does that equal 0.0623?
It should equal 0.063 if you do 0.3*0.21, the answer is right but it was just complicating to do :/