David's dinner costs $24. He wants to leave a 20% tip. The tax rate is 8%. What is the total he will pay?

The measure of one angle of an octagon is two times smaller that of the other seven angles. what is the measure of each angle?

Is the power produced directly proportional to the wind speed, give reasons for your answer?

Timmy uses 1 1 2 cups of sugar for every 2 gallons of lemonade he makes. how many cups of sugar would timmy use if he makes 13 gallons of lemonade?