She must be rich. Look at her house and the car! They're brilliant!
She must have won a lot of money on the lottery. She's been playing Thunderball ever since it was launched.
You must be joking saying that you've failed your Matura exam! You scored 100% in the mock test.
She can't be rich. Look at her clothing. Even Brad, the homeless guy, is wearing better clothes.
She can't have won millions on the lottery. She can't even afford a new car.
You can't be serious saying that you've passed your driving test. You were awful while practising for the test!