3x - 1 = 20
3x = 21
x = 7
Your answer is D) 7.
Whenever you have a decision tree like this, the probability of reaching a specific leaf is the multiplication of the probabilities of each step you have to reach the leaf.
So, in order to reach the "hardcover and nonfiction" leaf, we have to take the "buys hardcover" branch (probability 0.35), and then the "buys nonfiction" branch (probability 0.55).
Given what we said above, the probability for "hardcover and nonfiction" is

The answer is the last option
Which is (49x-16)^2
Answer:
Option C is correct
P(A or B) = 0.65
Step-by-step explanation:
<u>Given:
</u>
P(A) =0.5
P(B)=0.30
P(A and B) =0.15
( The probability of the happening of both independent events will be there product) P( A and B ) =P(A).P(B)
<u>Solution:</u>
To find the probability of the Happening of event A either event B we will use the following formula
P(A or B) = P(A) + P(B)-P(A and B)
= 0.5 + 0.3 - 0.15
=0.65