Suppose there are ten balls in an urn, four blue, four red, and two green. The balls are also numbered 1 to 10. How many ways are there to select an ordered sample of four balls without replacement such that the number B 0 of blue balls, the number R 0 of red balls, and the number G 0 of green balls are all different?

• 2144
• 1152
• 864
• 1446
• 256

A graph is a set of points, called?

• fields
• Nodes
• Edge
• lines

In the following relation {(a, a),(a, b),(b, a),(b, b),(b, d),(c, c),(d, b),(d, d)} A = {a, b, c, d}, which of the following is not true?

• this relation is symmetric since the reverse of every non-reflexive element is present.
• this relation is also transitive by checking all overlapping pairs.
• this relation is reflexive, since (0, 0),(1, 1),(2, 2),(3, 3),(4, 4) R.
• None of these