7. Personal Finance

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?

Suppose the local sales tax rate is $6.5\%$ and you buy a car for $\$12,500$. What is the car's total cost?

Hint: Find how much tax is due first.

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?

If sales tax on a \$36 pair of shoes is \$1.26, find the sales tax on a $\$250$ pair of shoes.

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

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?

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?

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.

Carson bought some new sneaker on sale for $\$250$. The sale price was $65\%$ of the original price. What was the original price?

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

Saphia's lunch bill was $\$17.65$. She wants to leave an $18\%$ tip. How much should the tip be?

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