Answer:the probability that exactly five customers make a purchase is 0.033
Step-by-step explanation:
The formula for binomial distribution is expressed as
P(x = r) = nCr × q^(n - r) × p^r
Where
p = probability of success
q= probability of failure
n = number of sample
From the information given,
39 percent of all customers who enter a store will make a purchase. It means that the probability of success, p = 39/100 = 0.39
The probability of failure q, would be 1 - p = 1 - 0.39 = 0.61
n = 6
The probability that exactly five customers make a purchase is expressed as
P(x = 5) = 6C5 × 0.61^(6 - 5) × 0.39^5
P(x = 5) = 6 × 0.61× 0.39^5 = 0.033
You can use the quadratic equation to solve this once you have this set equal to zero. The answers would be roughly 9.6 and -0.6.
Answer:

Step-by-step explanation:
There are only 2 solutions for none of the rooks can capture any of the other rooks: only if they are laid out in either of the 2 diagonal of the chess board
The number of possible combination for the rock to laid out in 8x8 (64 slots) chess board
possible combination
So the probability is pretty thin

There are 30 new cars and 90 used cars in the dealership.
120/4=30 new
120-30=90 used
I think that would be q-15?