Question

A contractor wishes to build 9 houses, each different in design. In how many ways can he place these homes on a street if 6 lots are on one side of the street and 3 lots are on the opposite side?​

Answer 1

Answer:

Here the concept of Permutation will be used -

9P1 = 9! ways

That is 9×8×7×6×5×4×3×2×1