An mp3 player costs $40, and a sales tax of $2.40 is added to the cost. what is the sales tax rate? (answer in %)

Me with this one question, and i'll upvote the brainliest answer

You're locked out of your house. the only open window is on the second floor, 25 feet above the ground. there are bushes along the edge of the house, so you will need to place the ladder 10 feet from the house. what length ladder do you need to reach the window?

Find the dimensions of the circle. area = 64π in.² r= in.