In the problem we have 2 periods 2004-2006 (3 years) and 2007-2012 (6 years).

For the first period the average revenue is (1100+700+300)/3=700

The average costs is (400+900+500)/3=600

So, the average profit is 700-600=100

Let assume that both revenue and costs increased in the second period by x percents. Then new average revenue for 2007-2012 is 700(1+x/100), new average costs is 600(1+x/100).

To calculate average profit for the whole total period 2004-2012 we need to sum all revenues, subtract all costs and divide by 9.

Total revenues=3*700+6*700(1+x/100)

Total costs=3*600+6*600(1+x/100)

Total profit=3*100+6*100(1+x/100)

Average profit=Total profit/9=100/3+200/3(1+x/100)

We know that it is equal to 300

100/3+200/3(1+x/100)=300

200(1+x/100)=800

1+x/100=4

x=300

So, both revenue and costs increased by 300% in the second period, thefore the ratio of revenues is 1/4.

The answer is C

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