Three red cards are numbered 1, 2, and 3. three black cards are numbered 4, 5, and 6. the cards are placed in a box and one card is picked at random.

find the probability that a black card was picked given that the number on the card was a even number.

Adecorative window is made up of a rectangle with semicircles at either end. the ratio of ad to ab is 3: 2 and ab is 30 inches. what is the ratio of the area of the rectangle to the combined area of the semicircles? possible answers: a. 2: 3 b. 3: 2 c. 6: π d. 9: π e. 30: π