<Tr> <Th> Month </Th> <Th> Exchange rate </Th> </Tr> <Tr> <Td> Sep 2007 </Td> <Td> 600,000 </Td> </Tr> <Tr> <Td> Oct 2007 </Td> <Td> 1,000,000 </Td> </Tr> <Tr> <Td> Nov 2007 </Td> <Td> 1,500,000 </Td> </Tr>

1 us dollar is equal to how many zimbabwean dollars