A smartphone originally costs \$800. It is on sale for \$680. Calculate the percent discount.

Last season, a farmer harvested $500\mathrm{kg}$ 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?

A reservoir's water level decreased by $20\%$ over the summer due to evaporation. If the water level is currently at $120$ million liters, how much water was there initially?

A square garden has sides of $8\mathrm{ft}$. The gardener reduces each side by $1\mathrm{ft}$ to make space for a pathway. What is the percent decrease in the perimeter of the garden?

A pair of running shoes costs $\$80$. The store is offering a $25\%$ discount. Calculate the amount of discount and the sale price of the shoes.

A patient was prescribed a medication dose. It was increased by $15\%$ after $3$ days, and the new dosage is $23\mathrm{cc}$. What was the original dosage?

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?