Answer:
your sister would be 35
Step-by-step explanation:
Sorry for the bad handwriting.
Answer:
(a)
The values of X can be 0, 1, 2 , ..., 10 . So, X is a discrete random variable.
(b)
The distribution of X is Binomial distribution with the parameters n = 10 and p = 0.2
(c)
Probability that no one or one person will be injured = P(X = 0) + P(X = 1)
= 10C0 * 0.20 * (1 - 0.2)10-0 + 10C1 * 0.21 * (1 - 0.2)10-1
= 0.810 + 10 * 0.2 * 0.89
= 0.3758096
(d)
Average value of X = np
Average value of X = 10 * 0.2 = 2
(e)
Variance of X = np(1-p)
Variance of X = 10 * 0.2 * (1 - 0.2) = 1.6
(f)
Number of ways in which 2 people gets injured = 10C2 = 10! / ((10-2)! 2!) = (10 * 9) / (2 * 1) = 45
Assume the best player got injures, number of ways in which one people out of remaining 9 people gets injured = 9C1
= 9! / ((9-1)! 1!)
= 9
Probability that the best player got injured = Number of ways in which 1 people gets out of 9 and best person gets injured / Number of ways in which 2 people gets injured
= 9 / 45
= 0.2
