help anyone .!!!which of the following correctly describes the variation in the equation A=nr^2?

Question

anonymous · Answer

A) A varies jointly with N and R
B)A varies directly with N and R 
C)A varies directly with R
D) A varies inversly with R

anonymous · Answer

c

anonymous · Answer

how do you know that? can you kind of explain it ?

jigglypuff314 · Answer

I really am not sure of this at all...
but I thought inverse was when something = 1/(variable)
and directly when just multiplication like = (number)(variable)
so since there's no division it can't be inversely at all...
then... the problem with B might have been that
it should have been A varies directly with R^2
which might leave you with C... but I might be wrong... :/

anonymous · Answer

well it will be an educated guess at least thank you though

anonymous · Answer

can you help me with another problem?

jigglypuff314 · Answer

I can try :)

anonymous · Answer

marcus can walk 1 mile to teh library in teh same time he can bicycle 2.5 miles to teh sporting goods store. His speed on the bicycle is 6 mi/h faster than his walking speed. what is his speed walking?

jigglypuff314 · Answer

figure out how much time it would take for him to bike 2.5miles using the speed given

anonymous · Answer

ok im getting 13 mi/h?

jigglypuff314 · Answer

hmmm? how?
I would think that walking should be slower than biking?

anonymous · Answer

nvm is it 5.2?

jigglypuff314 · Answer

I'm not sure how you're getting that?...
   2.5 divided by 6 = ?
then do 1 divided by ^ = ?

anonymous · Answer

4

jigglypuff314 · Answer

I'm not sure how you're getting those numbers...?

   2.5 divided by 6 = 0.41666
then do 1 divided by ^ = 2.4

anonymous · Answer

these are the only answers listed in the answer document :( 
A)10mp
B)13mp
C)5.2mp
D)4mp

jigglypuff314 · Answer

oh I see what I did wrong... gimme a sec then...

anonymous · Answer

ok

jigglypuff314 · Answer

got it :)
  2.5        1
----- = ---           solve for x 
 x+6        x

jigglypuff314 · Answer

letting x = walking speed
x+6 = biking speed
and distance divided by speed = time
and we were told that times were equal to each other

anonymous · Answer

soo its D?

anonymous · Answer

or c

jigglypuff314 · Answer

did you do the math? :P

jigglypuff314 · Answer

D would be correct :P

anonymous · Answer

lol thank you :)) .!!!!

jigglypuff314 · Answer

you're welcome :)

anonymous · Answer

i apreciate your time