The piggy bank
You have stealthily raided your small child’s piggy bank. You feel slightly guilty as you count the money you have the same number of dimes and quarters, totaling exactly $2.45. When you turn honest and put it back, how many of each coin will you need to replace? (Your child keeps a record of how much she puts in and in what denomination, of course).
Click here for the solution
Seven of each coin.
The engineering department was arranging for a rather expensive catered lunch to bid farewell to their retiring colleague. They calculated that it would cost each person $30. One good mathematician remarked, "It's lucky that there aren't five fewer of us to split the...