Aclub has 4 members. from these members, the positions of president and vice president have to be filled. in how many different ways can these 2 positions be filled?

Two lines that do not intersect are skew. always sometimes or never

Amerchant has coffee worth $60 a pound that she wishes to mix with 50 pounds of coffee worth $90 a pound to get a mixture that she will sell for $70 a pound. how many pounds of the & 60 coffee should be used?

In the diagram, the ratio of ab to ae is (1/2) . what is the ratio of the length of to the length of ?