If x-7 =0
Then x =7
Substitute x=7 into f(x):
2(7)^2 - 11(7) + k
= (98-77)+k
= 21+k
Therefore k=-21 because 21+(-21)=0
Answer:
0.1333 = 13.33% probability that bridge B was used.
Step-by-step explanation:
Conditional Probability
We use the conditional probability formula to solve this question. It is

In which
P(B|A) is the probability of event B happening, given that A happened.
is the probability of both A and B happening.
P(A) is the probability of A happening.
In this question:
Event A: Arrives home by 6 pm
Event B: Bridge B used.
Probability of arriving home by 6 pm:
75% of 1/3(Bridge A)
60% of 1/6(Bridge B)
80% of 1/2(Bridge C)
So

Probability of arriving home by 6 pm using Bridge B:
60% of 1/6. So

Find the probability that bridge B was used.

0.1333 = 13.33% probability that bridge B was used.
7/4 you do this because, for example you can think of it like pizza and pizza slices. You have 1 pizza and 3/4 of a pizza, let’s say each slice is 1/4 of a pizza. How many slices do you have altogether? Seven. You can also think of 1 as 4/4, so the just add 3/4 + 4/4 (which is technically just 3+4) = 7/4