Angela spent 3/8 of her money on 3 books and 9 pens. The cost of
each book is 4 times the cost of each pen. She bought some more
books with 4/7 of her remaining money.
(a) How many pens can Angela buy with 3/8 of her money?
(b) How many books did Angela buy altogether?
(c) If each pen cost $1.50, how much money did Angela have at first?