Use of Percentage: แบบฝึกหัด

A company had \( 120 \) employees last year. This year, the number of employees decreased by \( 15\% \). How many employees does the company have now?

A company's annual revenue was \( \$800,000 \) in 2021. In 2022, the revenue increased by \( 15\% \). However, in 2023, the revenue decreased by \( 10\% \) compared to 2022. What was the company's revenue in 2023?

Mr. Chan deposits a sum of money into a bank at an interest rate of \(4\%\) per annum, compounded half-yearly. If the total interest earned after one year is \(\$808\), find the principal amount deposited.

If the value of a machine depreciates by \( 12\% \) each year, what is the value of a machine originally worth \( \$50,000 \) after one year?

Mr. Chan deposits \( \$20,000 \) into a bank account that pays a simple interest rate of \( 4\% \) per annum. How much interest will he earn after 3 years?

A store owner marks up an item by \( 60\% \) above the cost price. During a clearance sale, he offers a discount of \( 40\% \) on the marked price. Determine the overall percentage profit or loss based on the cost price.

The population of a city grew by \( 2\% \) in 2022 and then by \( 5\% \) in 2023. If the population was 420,000 at the end of 2023, find the population at the beginning of 2022, correct to the nearest hundred.

A technician's monthly salary was increased by \( 15\% \) to \( \$27,600 \). Find his original salary before the increase.