One inlet pipe can fill an empty pool in 8 hours, and a drain can empty the pool in 20 hours. How long will it take the pipe to fill the pool if the drain is left open? hours:

What are different types of statistical programs

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?

Due to financial difficulties the owner of 4 skateboard stores is going to close 2 of his stores. based on the money earned at each store, which two stores should remain open?