Navigating Percent Word Problems: Sales Tax and Discounts

The video tutorial explains how to solve word problems involving percentages, focusing on sales tax, discounts, and depreciation. It introduces a formula to simplify these calculations, demonstrating its application through various examples, such as calculating the total price with sales tax, determining new prices after discounts, and finding original prices from totals. The tutorial also covers car depreciation over multiple years, emphasizing the importance of step-by-step calculations.

John buys a laptop for $299. What is the total price he pays if a 6% sales tax is added?

• $299.00

• $316.94

• $317.00

• $315.00

What is the decimal equivalent of 6%?

• 0.6

• 6.0

• 0.06

• 0.006

Which formula can be used to find the new price after applying a percentage increase or decrease?

• New Price = Original Price + r

• New Price = Original Price - r

• New Price = Original Price / (1 ± r)

• New Price = Original Price * (1 ± r)

Sally is currently paying $250 per month for car insurance. What will be her new monthly premium after a 20% good student discount?

• $180

• $250

• $220

• $200

What is the decimal form of 20%?

• 0.2

• 2.0

• 0.02

• 0.002

Karen pays $69.55 for a shirt with 7% sales tax included. What is the original price of the shirt?

• $65.00

• $70.00

• $75.00

• $60.00

What is the formula to find the original price when the final price and sales tax percentage are known?

• Original Price = Final Price - r

• Original Price = Final Price / (1 + r)

• Original Price = Final Price * (1 + r)

• Original Price = Final Price + r

Gerald buys a car worth $25,000. What is the value of the car after it depreciates by 15% in the first year?

• $21,250

• $23,000

• $22,000

• $20,000

What is the value of Gerald's car after it depreciates by an additional 10% in the second year?

• $19,125

• $20,000

• $21,000

• $18,000

Why can't we simply add the 15% and 10% depreciation rates to find the total depreciation over two years?

• Because the car's value increases over time.

• Because the car's value remains constant.

• Because the depreciation rates are too small.

• Because percentages are not additive in this context.