Last year, sales at a bookstore increased from $5,000 to $10,000. This year, sales decreased to $5,000 from $10,000.



What percentage did sales increase last year?

What percentage did sales decrease this year?

Verified Answer :

  • The percentage increase for last year is calculated as \(\frac{10,000 - 5,000}{5,000} \times 100\% = \boxed{100\%}\).
  • The percentage decrease for this year is calculated as \(\frac{10,000 - 5,000}{10,000} \times 100\% = \boxed{50\%}\).

Explanation

  1. Calculate Percentage Increase for Last Year

To determine the percentage increase for last year, we identify the initial sales value and the final sales value. The initial sales were \(I_1 = \$5,000\) and the final sales were \(F_1 = \$10,000\). The formula for percentage increase is given by \(\frac{F - I}{I} \times 100\%\). Substituting the values, we have \(\frac{10,000 - 5,000}{5,000} \times 100\% = \frac{5,000}{5,000} \times 100\% = 100\%\). Thus, sales increased by \(100\%\) last year.

  1. Calculate Percentage Decrease for This Year

To determine the percentage decrease for this year, we identify the initial sales value and the final sales value. The initial sales were \(I_2 = \$10,000\) and the final sales were \(F_2 = \$5,000\). The formula for percentage decrease is given by \(\frac{I - F}{I} \times 100\%\). Substituting the values, we have \(\frac{10,000 - 5,000}{10,000} \times 100\% = \frac{5,000}{10,000} \times 100\% = 0.5 \times 100\% = 50\%\). Thus, sales decreased by \(50\%\) this year.

Examples

Understanding percentage changes is essential in financial management and personal budgeting. For example, if a store tracks its revenue changes from month to month, calculating these percentages helps managers identify growth trends or periods where business performance slowed down. This allows for informed decision-making, such as adjusting marketing strategies during a sales dip or celebrating significant growth after a successful campaign.