1. A physiologist wants to test the effects of exercise and meditation on blood pressure. She devises four different exercise programs and three different meditation programs. If she wants 10 subjects for each combination of exercise and meditation program, how many volunteers must she recruit?
2. Handshakes Two 10-member basketball teams play a game. After the game, each of the members of the winning team shakes hands once with each member of both teams. How many handshakes take place?
3. Band Selections In how many ways can a band play a set of three waltzes and three tangos without repeating any song, such that the first, third, and fifth songs are waltzes?
4. Six houses in a row are each to be painted with one of the colors red, blue, green, and yellow. In how many different ways can the houses be painted so that no two adjacent houses are of the same color?
5. A furniture manufacturer makes three types of upholstered chairs and offers 20 fabrics. How many different chairs are available?