Related Clues:

• 'Certainly!'
• 'Okey-doke'
• Verifiable
• "You bet!"
• "No problemo!"
• 'Works for me'
• Sarcastic reply to an assurance
• Foolproof
• 'Whatever!'
• 'That'll be the day!'
• Doubt-free
• "Baloney!"
• 'Like that's gonna happen!'
• Doubter's scoff
• "Yeah, right"