nidhis.1408 wrote:Company z only sells chairs and tables. What percent of its revenue in 2008 did company z derive from its sales of tables?

S1.) In 2008, the average price of tables sold by Company Z was 10% higher than the average price of chairs sold by company z.

S2.) In 2008, Company z sold 20% fewer tables then chairs.

Can somebody give a simple explanation to this problem. Manhattan Gmat asks us to use the mixture problem approach as there are 2 components of company z.But i am not able 2 feel comfortable with the solution they have provided!

Statement 1: In 2008, the average price of tables sold by Company Z was 10% higher than the average price of chairs sold by company.
No information about the ratio of the number of tables sold to the number of chairs sold.
INSUFFICIENT.

Statement 2: In 2008, Company Z sold 20% fewer tables then chairs:
No information about the ratio of the selling price of the tables to the selling price of the chairs.
INSUFFICIENT.

Statements 1 and 2 combined:
Plug in two different combinations that satisfy both statements.
If (table revenue)/(total revenue) is the same in each case, then the two statements combined are sufficient.
If (table revenue)/(total revenue) changes, then the two statements combined are insufficient.

Case 1:
Chair price = 10, table price = 11.
Number of chairs sold = 10, number of tables sold = 8.
Table revenue/total revenue = (11*8)/(10*10 + 11*8) = 88/188.

Case 2:
Chair price = 20, table price = 22.
Number of chairs sold = 100, number of tables sold = 80.
Table revenue/total revenue = (22*80)/(20*100 + 22*80) =176/376 = 88/188.

Since the ratio in each case is the same, the two statements combined are SUFFICIENT.

The correct answer is C.