The correct answer for the given problem above would be option B. Fran must work 17 hours per week to meet her goal. Why? According to the given details above, Fran works 15 hours per week for $225 which makes it $15 per hour. If she adds another 2 hours per week to make it 17 hours, then she will earn $255 dollars per week. Now, since she is saving $40 dollars plus the two hours which is $30, a total of $70 per week of savings, multiplied by 20 weeks, then, she will be able to get $1,400.
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

8 / 6.403 = 1.249...
nearest tenth = 1.2
Step-by-step explanation:
Matrix has 5 rows and 3 columns.
So it's order is 5x3.