My solution to this problem is posted on the Web site.

The only correct way to solve the problem (and the only way to get full credit) is to mathematically show the condition on T. This condition falls out directly from the expressions for the two outputs. Those who wrote the correct expressions, but then appealed to graphical methods to get the final solution, usually ended up with 4/5.

Many folks fell into the trap of assuming that aliasing was not occurring in either system (``by the sampling theorem''), but remember that the sampling theorem only states that to properly reconstruct a signal, a certain sampling rate must be used. It does not say that this condition is satisfied in Prof. Bovik's Problem of the Week #3.

Tom