Answer:
first one
Step-by-step explanation:
The sum of n terms of a geometric sequence with first term "a" and common ratio "r" is given by

You have a=21, r=3, so the sum of 10 terms is

The appropriate choice is the 2nd one:
620,004
Answer:
μ = 1 The firm expects that one oil exploration will be successful.
v(x)= 0.9
Step-by-step explanation:
The first step is to define the random variable x as:
x: number of oil explorations being succesful
Then x can be take this values:
x = 0 , x =1 ... x =10
x is a binomially distributed random variable with parameters.
p = 0.1 and n=10
And the mean or the expected value of x is:
μ = E(x) = np
Then μ = 10*0.1 = 1
And the variance of x is:
V(x) = np(1-p)
V(x) = 10(0.1)(1-0.1)= 0.9
Since multiplicative inverse is the same thing as reciprocal, the multiplicative inverse is just the denominator and the numerator flipped. So the multiplicative inverse of -7/9 is 9/-7. Hope this helps! If you ever need any more help in math you could always DM me.
I don't see any pattern but if there has to be then it could be that the temperature is increasing and never dropped down.