Question

The number of cars at a car dealership is reduced by 10% in the first sales quarter of the year. If the number of cars decreased an additional 20% over the second sales quarter of the year, then by what percent did the number of cars decrease over the two sales quarters? A) 25% B) 28% C) 30% D) 45% ​

Answer 1

• B) 28%

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Let the initial price be x.

After the first sales quarter the price is reduced by 10% and became:

• x - 10% =
• x - 0.1x =
• 0.9x

After the second sales quarter the price is reduced by 20% and became:

• 0.9x - 20% =
• 0.9x - 0.2*0.9x =
• 0.9x - 0.18x =
• 0.72x

The decrease over the two quarters is:

• x - 0.72x =
• 0.28x

This is equivalent of 28%, hence the correct answer choice is B.