4 How many different ways can four Presidents and Vice Presidents stand in a line for a picture if:
a) There are no restrictions?
b) Every President and Vice President must stand together?
c) There must be four Presidents in the middle four positions?
Can anyone help me?

Ammonia molecules have three hydrogen atoms and one nitrogen atom.how many of each atom arein five molecules of ammonia

Which statement about the annual percentage rate (apr) is not true?

50 people men and women were asked if they watched at least one sport on tv. 20 of the people surveyed are women, but only 9 of them watch at least one sport on tv. 16 of the men watch at least one sport on tv. make a a two-way table and a relative frequency table to represent the data.