<Tr> <Td> Sales Commissions </Td> <Td> $18,802 </Td> <Td> $40,050 </Td> <Td> $0 </Td> </Tr> <Tr> <Td> Delivery Charges </Td> <Td> $900 </Td> <Td> $8,084 </Td> <Td> $5,000 </Td> </Tr> <Tr> <Th> Total Variable Costs </Th> <Td> $89,732 </Td> <Td> $149,034 </Td> <Td> $65,004 </Td> </Tr> <Tr> <Th> Contribution Margin </Th> <Td> $30,668 </Td> <Td> $53,016 </Td> <Td> $74,998 </Td> </Tr>

1. the difference between contribution margin and income from operations is