5d(7-3)= 20d
20d-16d= 4d
3x2d= 6d
4d+6d= 10d
the answer you are looking for is 10d
From the very beginning, each door had a 1/3 probability chance to be holding the grand prize. And the fact that she saw the consolation prize behind one of them does not change this probability.
From the beginning, all doors had equal chances.
Based on this, the answer to your question would be:
She could either accept or not accept the host's offer <span>because the probabilities of the three doors were equal from the beginning.</span>
