Answer:
25%
Step-by-step explanation:
solved by a system of equations in two variables.
Hey don't cry . I'm not good at math either but try to take a deep breath.
Answer:
The probability of SFS and SSF are same, i.e. P (SFS) = P (SSF) = 0.1311.
Step-by-step explanation:
The probability of a component passing the test is, P (S) = 0.79.
The probability that a component fails the test is, P (F) = 1 - 0.79 = 0.21.
Three components are sampled.
Compute the probability of the test result as SFS as follows:
P (SFS) = P (S) × P (F) × P (S)

Compute the probability of the test result as SSF as follows:
P (SSF) = P (S) × P (S) × P (F)

Thus, the probability of SFS and SSF are same, i.e. P (SFS) = P (SSF) = 0.1311.
Answer:
7/23
Step-by-step explanation:
There seven black socks and all of the socks together is 23.