Diego spent 1/3 of an hour playing on his phone, which used up 1/9 of his phone's full battery. How long could he play on his phone to use up his entire battery?

180 min or 3 hours

Step-by-step explanation:

1/3 of 60 min is 20 min

20 min for 1/9

x min for 9/9

x=(9/9*20)/(1/9)

x=(180/9)/(1/9)

x=180/9 * 9/1

x=180

the answer   is 200

step-by-step explanation:

this is a problem about poisson probabilities.   i don't know if you've

already studied poisson distributions, or if you have a place to look

to read more about the subject.  

here's how you can see a poisson distribution coming.   when there are

a lot of events that may happen at any time (or any place), and when

you're counting how many of them happen at a particular time (or a

particular place), and each event is independent of the others, then

the result is a poisson distribution.   this is roughly true for the

chocolate chips; one chip being in a cookie has only a small effect on

the probability that another chip will be in the cookie.

once you know you have a poisson distribution, you know a lot.   there

is only one parameter to a poisson distribution, so if you know the

mean, you know everything.   the form of the distribution is

  probability of n chips = {[e^(-x)]*(x^n)} / (n! )