I had a total of 80 pieces of 20¢ coins or 50¢ coins in a box. I used 50% of 20¢ coins and 25% of 50¢ coins to buy a book and had 46 coins left. (a) Find the percentage of the number of 20¢ coins at first. (b) Find the cost of the book.
number of 20c coins = x
number of 50c coins = 80-x
1/2(x) + 1/2(80-x) = 80 - 46
Solve for x :))
=^._.^=
+313 
