A 10-year government bond paid 5.8% simple interest per year. Over the 10 years, the bond earned \$4,640 in interest. What was the principal of the bond?

The bookstore buys a set of novels for \$120 and sells it for \$150. What percent did they mark up?

In a city, the water company increased the monthly water bill by 8%. The initial monthly cost is \$54. What is the cost after the increase?

The student council borrowed \$1,275 from a local sponsor to organize a school event. The sponsor charges 6.5% simple interest per year. How much interest will the student council owe after a year?

A community center paid \$432 in simple interest after 3 years on borrowed funds for new equipment. The interest rate was 4.5% per year. What was the original amount borrowed?

Sofia plans to buy a car. Her loan statement indicates she will pay \$1,350 in interest for a 3-year loan at 9% simple interest per year. How much did Sofia borrow for the car?

A city’s population grew from 120,000 to 138,000 people in one year. What is the percent increase in population?

A smartphone originally costs \$800 but is now sold for \$680. Determine the percent decrease in price.

Last season, a farmer harvested 500 kg of rice. Due to improved techniques, the harvest is estimated to increase by 20% this season. How much rice is the farmer looking to harvest this season?