Q.A 2x2xn hole in a wall is to be filled with 2n 1x1x2 bricks. In how many ways can this be done if the bricks are indistinguishable?
let F(n) be the number of ways to fill the hole. Let's consider the following cases:
case 1: the first 2x2x1 part of the hole is filled by 2 bricks. There are two ways to fill this part with 2 bricks( either vertical or horizontal) and we have F(n-1) ways to fill ...
A recursive equation is used to find how many ways bricks can be placed in a hole in a wall. Diagrams are included with this well explained solution.