The environmental protection agency must visit nine factories for complaints of air pollution. in how many different way can a representative visit five of these to investigate this week?
a.15,120
b.362,880
c.5
d.126

When new rock is added to an oceanic ridge, the magnetized strips on either side of the ridge are evidence of sea-floor spreading. this is because the rocks on the two sides of the ridge o are equal in width and in polarity are polar opposites oare magnetized vary in width but are equal in polarity