Answer:
Hence the person stop at floor by at least one person will be
E(X)=(summation from K=1 to k)[1-{(k-1)/k}^n]
Step-by-step explanation:
Given:
There are n peoples and k floors in a building.
Selects floor with 1/k probability .
To find :
Elevator stop at each floor by at least one person.
Solution:
Now
let K= number of floor at which at least one person will be stopping.
For getting E(X)
consider a variable Ak =1 if a least one person get of the elevator
and values for k=1,2,3.....k
K=(summation From k=1 to k)Ak
E(K)=((summation From k=1 to k) E[Ak]
=(summation From k=1 to k)[
Hence the person stop at floor by at least one person will be
E(K)=(summation from K=1 to k)[1-{(k-1)/k}^n]
9514 1404 393
Answer:
[[274][895][136]]
Step-by-step explanation:
Starting with the middle row, we need a product of two single-digit numbers that is between 53-1 = 52 and 53-9 = 44. Possible products are 5×9=45 and 6×8=48. This means the number in the middle position in the left column must be 8 or 5.
The middle number in the left column cannot be 5, because we must be able to get -5 by subtracting that number from a sum that is at least 3 = 1+2. So, the middle number in the left column is 8, the other two numbers in that column are 1 and 2, and the other two numbers in the middle row are 5 and 9.
There is no product of single-digit numbers that is 30-1 = 29, so the upper left number must be 2, and the bottom left number must be 1. The other two numbers on the top row must be 4 and 7, so that row's equation is 2+4×7=30.
The only remaining digits are 3 and 6. In order to have -3 on the bottom row, the equation there must be 1×3-6 = -3. Then the middle digit must be divisible by 3, so must be 9.
Our solution is ...
row 1: 2 + 7 × 4 = 30
row 2: 8 + 9 × 5 = 53
row 3: 1 × 3 - 6 = -3
And that makes the column equations be ...
col 1: 2 - 8 + 1 = -5
col 2: 7 + 9 / 3 = 10
col 3: 4 × 5 - 6 = 14
Answer:
Minimum number of calls = 10
Step-by-step explanation:
Lets name the five people as A,B,C,D and E.
<u>On the night before ,each person talks to every other person atleast once that means A would talk to B,C,D and E atleast once.</u>
Lets start with A. He would talk to other 4 people which means there would be 4 phone calls made.
Now lets take B. He can talk to A,C,D and E. But A has already talked to C therefore to get minimum number of phone calls , B need not call A again. So he calls only C,D and E.
In case of C using similar logic he need to talk to only D and E.
For D , he talks to E alone.
E does not have to talk to anyone as he has already talked to everyone atleast once.
Total calls = 4 + 3 + 2 + 1
= 10
