There are 12 different routes from town A to town C. Since there are 3 roads connecting towns A and B, you have 3 options to start with. And since there are 4 roads connecting towns B and C, for each of the 3 options from town A, you have 4 options to choose from to get to town C. Therefore, you have 3 x 4 = 12 different routes to get from town A to town C.