The price for crude oil produced by the Organization of the Petroleum Exporting Countries (OPEC) fell for the Sixth day in a row Tuesday, to 55.90 dollars. On Tuesday, one barrel (159 liters) of OPEC crude was 0.90 dollars cheaper than on the previous day, when it stood at 56.80 dollars, the OPEC said on Wednesday, according to a report of DPA. OPEC calculates an average basket price based on 13 important brands produced by its members
