How many jars can be in the first place? 12 In the second place? 11 (as one is already in the first place) Third? 10 and so on. For each put in the first place you can choose 11 in the second and 10 in the third and so on. Thus the solution is 12*11*10*9*8*7*6*5*4 or a simpler way to write 12!/3!
