There are 8 weeks and 18 books. therefore you would multiply these numbers together. 
the answer would be 144 different combinations.
not sure about the permutation or combination notation, but I got you on the first part!
        
             
        
        
        
Answer:
so, i have a method of multiplying fractions, but im not going to strait give you the answer
Step-by-step explanation:
multiply the whole number (1) by the denominator (3) and then add it to the numerator (1).
you multiply the fractions from there.
this is a very fun way of doing fraction multiplying with mixed numbers!
have a good day! :D
 
        
                    
             
        
        
        
Answer:
k = (6/15)
Step-by-step explanation:
The equation is:
6*(x + 1) + 2 = 3*(k*5*x + 1) + 3
To have no solutions, we need to have something like:
x + 7 = x + 4
where we can remove x in both sides and end with
7 = 4
So this equation is false, meaning that there is no value of x such that this equation is true, then the equation has no solutions.
First, let's try to simplify our equation:
6*(x + 1) + 2 = 3*(k*5*x + 1) + 3
6*x + 6 + 2 = 3*k*5*x + 3*1 + 3
6*x + 8 = 15*k*x + 6
if 15*k = 6, then the system clerly has no solution.
then:
k = 6/15
then we get:
6*x + 8 = (6/15)*15*x + 6
6*x + 8 = 6*x + 6
8 = 6
The system has no solutions.
 
        
             
        
        
        
The minimal completion time for the activities is the shortest possible time for all the activities to be finished. In doing this, we look at the path that would require the greatest amount of time. At the START node, we choose the path that would take the longest which is 7 days leading to ACTIVITY D. Next, we choose the path leading to ACTIVITY B which takes 5 days. Then, we move to ACTIVITY C taking 5 days and finally, reach the END which would take 6 days. So, the minimal completion time is:
7 + 5 + 5 + 6 = 23 days