Thread: Algebra - Number Theory

My local charity shop was selling off books at 3 paperbacks for $1, 2 hard back for $1 , and $2 for coffee table books, I spent $30 for 30 books and I bought at least one of each book . How many books of each type did I buy?

Originally Posted by ciccio

My local charity shop was selling off books at 3 paperbacks for $1, 2 hard back for $1 , and $2 for coffee table books, I spent $30 for 30 books and I bought at least one of each book . How many books of each type did I buy?

If , and denote the number of paper backs, hard backs and coffee table book bought we have:



and



Also is divisible by and is divisible by .

Now a bit of trial and error should be sufficient to find the solution.

CB