Question 1: A jar contains a nickel, a dime, and six quarters. Tom draws one coin from the jar, and then Mary draws a coin from those remaining. If the probability that Tom draws the nickel and Mary draws the dime is 1/x, what is the value of x?
Question 2: A box contains 7 blue marbles, 4 red marbles and 6 green marbles. How many additional blue marbles must be added in the box so that the probability of randomly drawing a blue marble is 1/2?
Question 3: If a is an integer chosen randomly from {3, 4, 5, 9} and b is an integer chosen randomly from {3, 8, 12, 15}, what is the probability that a/b is an integer?
Question 4: A box contains 3 yellow, 2 red, 4 green and 3 black marbles. Two marbles are taken one after the other at random from the box. What is the probability that both marbles are red?
Question 5: How many committees of 4 students can be selected from a group of 7 students?
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