A prize is hidden under one of five objects.
Shilpa is privately told the shape and Colin is privately told the color. Shilpa and Colin are mathematicians who use perfect logical reasoning, and the initial setup is common knowledge to both of them.
The host asks, “Do either of you know where the prize is?” Both of them are silent.
The host then asks, “Do you know now?” Again both of them are silent.
The host asks again, “Do you know now?” At this point both Shilpa and Colin simultaneously say, “Yes!”
Under which object is the prize?