Question

The population size of a country grows exponentially at a rate of 0.95% per
year. After how many years will the population have doubled in size?

Answer 1

@Luigi0210 please help

Answer 2

Hi luigi ;D

Answer 3

hello dwade~

And you don't have any other info given?

Answer 4

thats literally everything the question is asking

Answer 5

i don't know why they gave me such little info. im kinda confused

Answer 6

Well it's below 0.99 so it's a decay... >.>

Answer 7

Fizzy can help^

Answer 8

really? lol but wouldn't that change the question completely?

Answer 9

o_o

Answer 10

Yes... why I'm confused ;_;

Answer 11

copied and pasted that question so nothings a typo

Answer 12

did i mention my professor is kind of an idiot?

Answer 13

I honestly don't know, but I haven't done Math in almost 4 days D: So I keep doubting myself more then usual :l

@ganeshie8 might know how to solve this :>

Answer 14

alright cool hopefully he can see his bat signal im in desperate need of assistance right now

Answer 15

@freckles know whats up with this question?

Answer 16

@jim_thompson5910 @whpalmer4 @zepdrix

Answer 17

luigi think you could answer this one instead? The initial amount of a radioactive substance is 100 grams and is decreasing
exponentially at a yearly rate of 10%. In what year will there be half of the
substance left?

Answer 18

@Luigi0210 you there bro?

Answer 19

Yea, and I think you just plug that into the decay formula and work backwards
http://prntscr.com/3fd8wt
So we have \(50=100(.9)^x\) I think. Just solve for x.

Answer 20

No, it's 0.95% growth — that means \((1+\frac{0.95}{100})\) times the previous value each year. It is not a decay.

Answer 21

Oh I misread that >.<

Answer 22

\[2 = (1+\frac{0.95}{100})^n\]\[\log 2 =n \log 1.0095\]\[n = \frac{\log 2}{\log 1.0095}\]