Answer:
a. 20%
b. 40%
Explanation:
We have the following from the statement:
P (T) = 0.3
P (H) = 0.4
P (T n H) = 0.1
Thus:
a. Tornado-only probability would be the probability of a tornado minus the probability of both tornado and hucaran
P (only T) = P (T) - P (T n H)
replacing:
P (only T) = 0.3 - 0.1
P (only T) = 0.2
In other words, the probability that only one tornado will occur is 20%
b. The probability that there is neither of the two would be the complement of the union between both events, that is:
P (T U H) '= 1 - P (T U H)
and the union is equal to:
P (T U H) = P (T) + P (H) - P (T n H)
replacing:
P (T U H) = 0.3 + 0.4 - 0.1
P (T U H) = 0.6
now if replacing in P (T U H) ':
P (T U H) '= 1 - 0.6
P (T U H) '= 0.4
That is to say that the probability that neither of the two happens is 40%