Mathematics with a Calculator Flashcards

An electronics store is offering a 20% discount on a television that originally costs $1,250. If the sales tax is 13% (HST), what is the final price of the television after the discount and tax are applied?

Answer: $1,130.00

First, calculate the discount amount: $1,250 * 0.20 = $250. Subtract the discount from the original price to get the sale price: $1,250 - $250 = $1,000. Next, calculate the sales tax on the sale price: $1,000 * 0.13 = $130. Finally, add the sales tax to the sale price to find the final cost: $1,000 + $130 = $1,130.00.

A rectangular community garden has a length of 25.5 metres and a width of 15.2 metres. The organizers want to build a fence around the entire garden. What is the total length of fencing required in metres?

Answer: 81.4 metres

The length of fencing required is the perimeter of the rectangle. The formula for the perimeter of a rectangle is P = 2(length + width). Substitute the given values: P = 2(25.5m + 15.2m). First, add the length and width: 25.5 + 15.2 = 40.7 metres. Then, multiply the sum by 2: P = 2 * 40.7 = 81.4 metres.

A car travels at an average speed of 85 kilometres per hour. How long will it take the car to travel a distance of 446.25 kilometres?

Answer: 5 hours 15 minutes

To find the time, use the formula: Time = Distance / Speed. Time = 446.25 km / 85 km/h = 5.25 hours. To convert the decimal part of the hour into minutes, multiply it by 60: 0.25 * 60 = 15 minutes. Therefore, the total time is 5 hours and 15 minutes.

A recipe for a batch of 12 muffins requires 1.5 cups of flour. If you want to make 30 muffins, which of the following proportions correctly represents the amount of flour (x) needed?

Answer: 1.5 / 12 = x / 30

The relationship is a direct proportion. The ratio of flour to muffins must remain constant. The correct proportion is (flour for first batch) / (muffins in first batch) = (flour for second batch) / (muffins in second batch). This gives the equation 1.5 / 12 = x / 30.

A loan of $5,000 is taken out with a simple interest rate of 4.5% per year. What is the total amount of interest paid after 3 years?

Answer: $675.00

The formula for simple interest is I = Prt, where I is the interest, P is the principal amount ($5,000), r is the annual interest rate (0.045), and t is the time in years (3). I = $5,000 * 0.045 * 3. Calculating this gives: I = $225 * 3 = $675.00.

The volume of a cylindrical storage tank is given by the formula V = πr²h. If the tank has a radius (r) of 3 metres and a height (h) of 8 metres, what is its approximate volume? (Use π ≈ 3.14159)

Answer: 226.19 m³

Substitute the given values into the volume formula: V = πr²h. V ≈ 3.14159 * (3 m)² * 8 m. First, calculate the square of the radius: 3² = 9 m². Then, multiply the values together: V ≈ 3.14159 * 9 m² * 8 m. V ≈ 28.27431 * 8 m. V ≈ 226.19448 m³. The closest answer is 226.19 m³.