An urn contains 5 white ball and 8 black balls. 4 balls are randomly selected. a. with replacement, what is the probability that the first 3 are black and the 4 the is white?

Aquantity with an initial value of 3900 decays exponentially at a rate of 35% every hour. what is the value of the quantity after 0.5 days, to the nearest hundredth?

Water flows at a steady rate from a tap. its takes 40 seconds to fill a 4 litre watering can from the tap. the rate at which water flows from the tap is halved. complete: 4 litres into cm3

Barbara deposited $300 in the bank. if the bank pays her simple interest at the rate of 4 percent per year, how much money will she have in her account at the end of 9 months?