Question 145
Abelarda, Brunilda and Callisto, three old acquaintances, each want to buy a house among the 10 little houses in a row on the main street of the town. Since they cannot stand each other, they absolutely want to avoid being neighbors: they therefore want the houses they buy to be pairwise non-adjacent. In how many ways can they buy houses so as to satisfy this condition?
(A) 56
(B) 120
(C) 336
(D) 480
(E) 504
(A) 56
(B) 120
(C) 336
(D) 480
(E) 504