Question

By what percentage did the total book sales of the three stores increase from 2005 to 2010? 

• A. 12%
• B. 20%
• C. 33.3%
• D. 15%
• E. 25%

Hint:

Always use \(\frac{\text{increase}}{\text{original}} \times 100\) for percentage change.

Answer 1

The Correct Option is B

Step 1: Sales in 2005. 
Store A = 8, Store B = 12, Store C = 10. 
Total = \(8 + 12 + 10 = 30\). 
Step 2: Sales in 2010. 
Store A = 11, Store B = 13, Store C = 12. 
Total = \(11 + 13 + 12 = 36\). 
Step 3: Increase. 
Increase = \(36 - 30 = 6\). 
Step 4: Percentage. 
\[ \frac{6}{30} \times 100 = 20%. \] Final Answer: 20%