A new car was bought for €24,000. It decreased in value by 20% in the first year. If it's value at the end of the second year was €16128, by what percentage did it's value decrease during the second year?

The first year it decreased by 20%. Multiply the cost of the car by 80% (100%-20% = 80%)

24,000 x 0.8 = 19200

After the first year the car was valued at €19,200

Now divide the value after the 2nd year by the value after the first year:

16128 / 1900 = 0.84 * 100 = 84%

The car is 84% of the value.

100 - 84 = 16

The cars value decreased by 16% during the second year.