This would depend on whether the salesperson knew the speed of printing that would be required of the machine. In case, the salesperson was aware of this requirement, the contract can be rescinded based on misrepresentation as the assurance given by the salesperson was not fulfilled. In the other case, if the salesperson was not aware of the speed that would be required from the machine, the contract may not get rescinded. The representative should have mentioned the speed that was required for the machine to work in their office.