It is
-25+21/2= -25/0 + 21/2 = -3/8
Answer:b and c
Step-by-step explanation:
Answer:
n(n+1)(n+5)/3
Step-by-step explanation:
there is no value, as we don't know n.
but we can create a summary formula/ function definition :
this is the sum for k = 1 to n of k×(k+3)
k×(k+3) = k² + 3k
so, the overall sum splits into the sum of k² for k=1 to n, and the sum of 3k for k=1 to n.
and the sum of 3k is 3 times the sum of k for k=1 to n.
Σk² for k=1 to n = [n(n+1)(2n+1)]/6
Σk for k=1 to n = n(n+1)/2
3×Σk for k=1 to n = 3×n(n+1)/2
so, we have a function formula
n(n+1)(2n+1)/6 + 3n(n+1)/2 = n(n+1)(2n+1)/6 + 9n(n+1)/6 =
= n(n+1)(2n+1+9)/6 = n(n+1)(2n+10)/6 = n(n+1)(n+5)/3
Answer:
Step-by-step explanation:
Definitions and concepts
The Poisson process is useful when we want to analyze the probability of ocurrence of an event in a time specified. The probability distribution for a random variable X following the Poisson distribution is given by:
And the parameter
represent the average ocurrence rate per unit of time
For this case we know that 
And we want the probability that during the next five minutes, three cars will arrive, so then our rate becomes:

And we want this probability:

And if we use the pmf we got:
Answer:
Minimum surface area =
Step-by-step explanation:
We are given that
Width of container=x cm
Length of container=2x cm
Volume of container=
We have to find the minimum surface areas that this container will have.
Volume of container=



Surface area of container=
Because the container does not have lid
Surface area of container=

Differentiate w.r.t x


Substitute 





Again differentiate w.r.t x

Substitute x=3.4

Hence, function is minimum at x=3.4
Substitute x=3.4
Then, we get
Minimum surface area =