: Swanton Welding is setting up the shop for a new production run. Nine welding machines are available but only three spaces are available in the production area of the shop. In how many different ways can the nine welding machines be arranged in the three available spaces?

Abag contains 4 red, 7 blue and 5 yellow marbles. event a is defined as drawing a yellow marble on the first draw and event b is defined as drawing a blue marble on the second draw. if two marbles are drawn from the bag, one after the other and not replaced, what is p(b|a) expressed in simplest form? a. 7/16 b. 7/15 c. 14/16 d. 14/15