Answer:
Step-by-step explanation:
Inverse variation is written as
which, in words, says "y varies inversely with x". If cavities varies inversely with time brushing, then

We are given the initial condition for which we need to solve for k:
c = 4 when t = 30:
so
k = 120.
Now we will use that value of k to solve the problem of how many cavities, c, would she have if she brushed her teeth 120 seconds, t, each night:
(the 120 on top is the k value and the 120 on the bottom is the number of seconds she brushed) to get
c = 1
Answer: 12,620,256
Step-by-step explanation:
Given: The camera shop socks eight different types of batteries and there re at least 31 batteries of each type.
Here we want to select r= 31 batteries from n= 8 kinds of batteries, then formula we use to find number of ways is 

Hence, the number of ways can a total inventory of 31 batteries be distributed among the eight different types = 12,620,256
Answer:
Emily , don't put your whole name in the questions :DDDD, it's at the top of the page, anyway, Eloper .. :DDD
Step-by-step explanation:
It's arithmetic b/c you're just adding 1
arithmetic
1
1
are the answers , the last one is b/c that's the common difference.
Answer: 5.04
Step-by-step explanation:
= 9.87
9.87 divided by 1.96 = 5.04