Solve.
 1) A collection of dimes and quarters is worth S15.25. There are 103 coins in all.
 How many of each is there?
 2) A collection of half dollars and nickels is worth S13.40. There are 34 coins in
 all. How many are there?
 3) The attendance at a school concert was 578. Admission was S2.00 for adults
 and S1.50 for children. The total receipts were S985.00. How many adults and
 how many children attended?
 4) A purse contains S3.90 made up of dimes and quarters. If there are 21 coins in
 all, how many dimes and how many quarters were there?
 5) A boy has S2.25 in nickels and dimes. If there are twice as many dimes as
 nickels, how many of each kind has he?