During the year, the store purchased additional armchairs.

Target question: What is the total amount spent by the store on the armchairs it had in stock at the end of last year?
Statement 1: Last year, the store purchased 30 armchairs for $500 each.
30 * 500 = $15000 was spent on getting additional 30 armchairs but we don't know the quantity sold and selling price. So we cannot evaluate the quantity left at the end of last year. Therefore, statement 1 is NOT SUFFICIENT.

Statement 2: Last year, the total revenue from the sale of armchairs was $16,500
The number of additional purchase is unknown, and the quantity of armchairs sold is not provided. So, the target question cannot be evaluated; thus, statement 2 is NOT SUFFICIENT.

Combining both statements together
From statement 1: Total additional armchair purchased = 30
From statement 2: Total revenue is $16,500
The total no. of armchairs sold to generate revenue of $16500 is unknown. Hence, the target question cannot be evaluated; therefore, both statements combined are NOT SUFFICIENT.

ANSWER = Option E