Step-by-step explanation:
W = Set of projects the guitarist wrote
P = Set of products he produced
A bass guitarist worked on 15 music projects last year.
Universal set = 15
He wrote and produced 5 projects.
W ∩ P = 5
He wrote a total of 9 projects.
W = 9
The Venn Diagram is given in the attached image.
a. How many projects he wrote but did not produce (W - P)?
W - P = W - W ∩ P
W - P = 9 - 5 = 4
He wrote 4 projects but did not produce them.
b. How many projects he produced but did not write (P - W)?
Universal set = (W - P) + (P - W) + W ∩ P
15 = 4 + (P - W) + 5
(P - W) = 15 - 9 = 6
He produced 6 projects but did not write them