Please give a detailed answer and explain the calculations you did. I'll give Brainliest!

Answer:
30 books
Step-by-step explanation:
He sold 75 books, and 40% of them were in his collection.
Find 40% of 75.
Just do 75 * 0.4 and you'll get 30
Answer:
188?
Step-by-step explanation:
40% of 188 is 75
75.2/188 = 40%