What modal we used to express 30%-50% sure the information we are talking about is true?

Choose Might, Must or Can't to fill the space. " To give the promotion to Harold was silly. He ____ know much about this company after only a year working here."

Choose Might, Must or Can't to fill the space. "Do you know where Carl is? He _____ be out - his car keys are on the table."

Choose Might, Must or Can't to fill the space. "He ____ be from Paris. He doesn't speak a word of French."

Choose Might, Must or Can't to fill the space. "Oh, the phone is ringing. Answer it. It _____ be Kate. She always rings at this time."

Choose Might, Must or Can't to fill the space. "I don't know why I am so tired these days. I ____ be working too hard, or maybe I am not sleeping too well."

Choose Might, Must or Can't to fill the space. "Go and look in the kitchen for your gloves. They _____ be in there."

Besides being 90%-100% sure it's true, what is the other factor that tells us the sentence needs "must"?

Choose Might, Must or Can't to fill the space. "Your mother ____ be a great cook. You are always so keen to get back home to eat!"

Choose Might, Must or Can't to fill the space. "You seem to know everything about the theatre. You ____ go every week."

How many Modal Verbs used in Modals of Deduction? What are they?

What modal we used to express 90%-100% sure the information we are talking about is true?