# Finding the final amount given the original amount and a percentage increase or decrease

In this lesson, we learn how to find a final amount, given an original amount and a percentage increase or decrease. The percentage increase may be a markup or profit or just increase in price. Similarly, the percentage decrease may be markdown or discount or loss.

Rules to find the final amount given the original amount and a percentage increase or decrease.

• First consider the original amount.

• Then consider the rate or percentage increase or decrease

• To find the markup or discount, multiply the rate by the original amount.

• To find the final amount, add or subtract the markup or discount from original amount.

The next model of a sports car will cost 6% more than the current model. The current model costs \$4,000. How much will the price increase in dollars? What will be the price of the next model?

### Solution

Step 1:

Current model price = \$40,000

Percentage increase in price = 6%;

Step 2:

Price increase in dollars = 6% of \$40,000 = 0.06 × 4000 = \$2400

Next model price = current model price + increase in price

= \$40,000 + \$2,400

= \$42,400

A store was selling lawn chairs at a unit price of \$48. The store further offered a 15% markdown on the price of the chair. How much would a chair now cost?

### Solution

Step 1:

Price of lawn chair = \$48

Markdown = 15% of \$48 = 0.15 × 48 = \$7.20

Step 2:

Price after discount = \$48 – \$7.20 = \$40.80