At a concert there needs to be at least 1 member of staff working for every 150 members of the audience. if there are 20 members of staff, how many people are in the audience?

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?

Acertain volume of water contains 100000 hydrogen atoms and 50,000 oxygen atoms how many hydrogen atoms are in a volume of water containing 4 million oxygen atoms

What is the point of inflection for the function f(x)=2cos4x on the interval (0, pi/2)