The average of 5,25, and y is 30. which of the following must be true?  
a) y < 25
b) 25 < y < 30
c) 30 < y < 40
d) 40 < y

To find the inverse of a number a, one can use the equation f(c) = a-1/c=0 where c is the inverse of a use the secant method of finding roots of equations to find the inverse of a = 2.5 ,er = 0.001%