Answer:
The expected number of floors the elevator stops at, not counting the ground floor is =
n*(1-(1-1/n)^m)
Step-by-step explanation:
Here, we want to know the expected number of floors the elevator stops at.
let X1,X2,X3,..Xn are indicator variable for which value =1 if at least one person stops on that floor otherwise value is 0
P(at least one person stops at floor Xj)=1-P(none of m people stops at floor j)
=1-(1-1/n)^m
here total number of floors on elevetor Stops X=X1+X2+X3+...+Xn
hence expected number of floors on elevetor Stops
E(X)=E(X1)+E(X2)+E(X3)...+E(Xn)
=(1-(1-1/n)^m )+(1-(1-1/n)^m )+(1-(1-1/n)^m )+(1-(1-1/n)^m )+..... n times
=n*(1-(1-1/n)^m)
Answer:
D. 
Step-by-step explanation:
We have been given that a bag contains x blue chips and y red chips. The probability of selecting a red chip at random is 3/7. We are asked to find the 
.
Since we are told that probability of selecting a red chip at random is 3/7, so red balls are 3 and total balls are 7:
Since total balls are 7, so we will get:
Upon substituting 
in expression , we will get:
Therefore, the value of is and option D is the correct choice.
Y=-0.5x²+1.25
To find the vertex we need to write given equation in the vertex form.
y=a(x-h)²+k
(h,k) - coordinates of the vertex
y=-0.5x²+1.25 can be written as
y=-0.5(x-0)²+1.25
So, h=0, k=1.25
Vertex is (0, 1.25)
Answer:
7
Step-by-step explanation:
2+4+3+4+3+4+5=25
32-25=7
The value of x is 3
Step-by-step explanation:
The value of x
4 : 9 = (5x + 13) : 63
we can write this as
Now we will cross multiply the values
