If 6 pennies are in each pile how many pennies are in nine piles?

There were 816 people at a concert when a band started to play. after each song, only half the people stayed to hear the next song. how many people were left at the concert after x songs? write a function to represent this scenario.

Find the area of the region that is inside r=3cos(theta) and outside r=2-cos(theta). sketch the curves.

According to the general equation for conditional probability if p(anb)=3/7 and p(b)=7/8 what is p(a i b)