The Probability Factor (1976)

In this black comedy, Fred (Jean-Louis Trintingnant) works for an insurance company as a computer engineer. Fred is bored with enduring the trials of his shrewish wife, so, after using actuarial tables to calculate the most common means of death, he cleverly prepares the family bathroom and brings about her demise. For a while he is content with his new freedom, but then he recognizes that a friend is in a similar situation.