Repeated Percentage Change in Real-World Scenarios

The video tutorial explains how to calculate the depreciation of a boat's value over three years using compound interest. It also covers how to determine the original salary before a percentage increase. The tutorial emphasizes the importance of understanding compound calculations and avoiding common errors, such as assuming a starting value of 100% when it has already been adjusted.

What is the initial value of the boat before any depreciation?

• 180,000 Hong Kong dollars

• 160,000 Hong Kong dollars

• 170,000 Hong Kong dollars

• 150,000 Hong Kong dollars

How do you represent a 4% depreciation as a decimal?

• 0.96

• 0.04

• 1.04

• 0.94

After three years of depreciation, what is the approximate value of the boat?

• 141,558 Hong Kong dollars

• 150,000 Hong Kong dollars

• 130,000 Hong Kong dollars

• 160,000 Hong Kong dollars

What is the percentage increase in Jelena's salary?

• 10%

• 5%

• 20%

• 15%

If Jelena's salary after a 5% increase is 252,000 Hong Kong dollars, what was her salary before the increase?

• 240,000 Hong Kong dollars

• 250,000 Hong Kong dollars

• 230,000 Hong Kong dollars

• 260,000 Hong Kong dollars

What is the key concept to remember when calculating percentage changes?

• Always start with 100%

• Ignore the percentage

• Use the given percentage directly

• Understand the context of the percentage

What common error should be avoided when calculating percentage changes?

• Multiplying by 100

• Rounding numbers

• Using a calculator

• Assuming the final value is 100%