If we increase 100 by 20% => 120, and then decrease 120 by 20% => 96; we notice the final value decreased by 4%
From the above scenario we can derive an important property, i.e. whenever there is a successive increase (p%) and decrease (q%) for the original value to be retained after final operation p has to be greater than q;
p>qAlernatively,
You can also solve this problem as follows, It is basically derivation of the above property

In the first year, i.e. 1999, the final value at the end will be \(9(12) (1+\frac{p}{100}) (1-\frac{q}{100})\)
In the coming three years, \((1+\frac{p}{100})(1-\frac{q}{100})\) will repeat 3 more times.
Final value at the end of 2002 = \(9(12) (1+\frac{p}{100})^4 (1-\frac{q}{100})^4\)
We're given, \((1+\frac{p}{100})^4 (1-\frac{q}{100})^4 = 1\)
\(1-\frac{q}{100}+\frac{p}{100}-\frac{pq}{100} = 1\)
p - q = pq
p and q are both > 0, therefore pq > 0
p - q > 0 => p > q
Therefore,
answer is c. p > q