Mr Roberts had 9512 in savings. He saved another 488.00 He then used all his money to buy 500 books. He sold the books for $35.00 each. How much dis Mr. Roberts earn from selling each book

9512 + 488 all divided by 500 = 20.  He spent 20 dollars per book.

If he sold each book for 35, and each book cost him 20, then he made $15 on each book.

Okay.

So he had $9512 and saved another $488 so,

9512 + 488 = 10000

He used that to buy 500 books so,

10,000 / 500 = $20 per book

He then sold the books for $35 each. If he paid $20 per book then $35 - $20 = $15

Mr. Roberts earned $15 per book by sellin

use this formula:

p(a\b) = p(a and b)/p(b).

take it from here.