Sentry Solutions sells security systems for $771. Sentry sources security systems from Single Source, Inc., for a variable cost of $511 per unit. What is Sentry Solutions' contribution margin in dollars for one security system?

Sentry Solutions sells security systems for $718. Sentry sources security systems from Single Source, Inc., for a variable cost of $465 per unit. What is Sentry Solutions' contribution margin as a percent of revenue? (Report your answer as a percent. Report 25.5%, for example, as "25.5".