Data Sufficiency

94. Find the percent change in the revenue generated by a salesman.
(1) When the salesman reduces the selling price of the product by 9.09%, the sales increase by 11.11%
(2) The number of units of the product sold before the change in price was 990


How would you approach this problem?


Explanation:
Let the SP of the article be 110x and the number of units sold be 90y. So, total revenue generated = 9900xy.
New SP after reduction of price = 100x
Number of articles sold after change in price = 100y
So, revenue generated after change in price = 10000xy
Hence, % change in revenue generated = (100xy/9900xy)*100 = (1/99)*100
Hence, the % change in the revenue is free from x and y; SUFFICIENT
Statement 2 is not sufficient because it provides no information about the change in price; NOT SUFFICIENT.
The correct answer is A;

This is a great approach, but I will say the wording of the question is pretty poor. 'sales increase by 11.11%' is a bit ambiguous