Front

What is simple interest?

Back

Simple interest is a method of calculating the interest charge on a loan or the interest earned on an investment based on the original principal amount and a fixed interest rate over a specified period of time.

Front

How do you calculate simple interest?

Back

Simple Interest = Principal x Rate x Time. For example, if you invest $1000 at a 5% interest rate for 3 years, the interest earned would be $1000 x 0.05 x 3 = $150.

Front

What is the formula to find the new price after a percentage decrease?

Back

New Price = Original Price - (Percentage Decrease x Original Price). For example, if a phone costs $200 and is discounted by 10%, the new price is $200 - (0.10 x $200) = $180.

Front

What does x + 0.07x represent?

Back

x + 0.07x represents an increase of 7% of x. It can be simplified to 1.07x.

Front

How do you calculate total cost including tax and tip?

Back

Total Cost = Meal Cost + Sales Tax + Tip. For example, for a $20 meal with 7% tax and a 20% tip on the meal cost, Total Cost = $20 + ($20 x 0.07) + ($20 x 0.20) = $25.40.

Front

How do you convert a percentage to a decimal?

Back

To convert a percentage to a decimal, divide by 100. For example, 13.2% as a decimal is 13.2 ÷ 100 = 0.132.

Front

What is the effect of a 9% decrease on a price p?

Back

The new price after a 9% decrease is represented as p - 0.09p, which simplifies to 0.91p.

Front

What is the difference between sales tax and tip?

Back

Sales tax is a percentage added to the purchase price by the government, while a tip is a voluntary amount given to service workers based on the service provided.

Front

If a meal costs $50 and the sales tax is 8%, what is the total cost?

Back

Total Cost = $50 + ($50 x 0.08) = $50 + $4 = $54.

Front

What is the formula for calculating percentage increase?

Back

Percentage Increase = (New Value - Original Value) / Original Value x 100%. For example, if a value increases from $50 to $60, the percentage increase is (60 - 50) / 50 x 100% = 20%.