Hi jjjinapinch,

We're told that Jazz and blues recordings accounted for 6 percent of the $840 million revenue from the sales of recordings in Country Y in 2000. We're asked for the revenue from the sales of jazz and blues recordings in Country Y in 1998.

1) Jazz and blues recordings accounted for 5 percent of the revenue from the sales of recordings in Country Y in 1998

While Fact 1 tells us the PERCENT of the revenue that Jazz and blues recordings represented in 1998, we don't know the TOTAL sales figures in 1998. Thus, we have no way to answer the question.
Fact 1 is INSUFFICIENT

2) The revenue from the sales of jazz and blues recordings in Country Y increased by 40 percent from 1998 to 2000

With the information in Fact 2, we can create the following equation:
(1.4)(Sales of Jazz and blues in 1998) = (.06)($840 million)

This is one variable and one equation, so we CAN solve for what the question asks for (and we don't have to perform the calculation to know that).
Fact 2 is SUFFICIENT

Final Answer: B

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Rich