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

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 ft. The gardener reduces each side by 1 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 smartphone originally costs \$800 but is now sold for \$680. Calculate the percent discount.

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?

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?