After a large number of drinks, a person has a blood alcohol level of 160 mg/dL (milligrams per deciliter). If the amount of alcohol in the blood decays exponentially, with one fourth being removed every hour, find the time it will take for the person's blood alcohol level to decrease to 20 mg/dL. (Round your answer to one decimal place.

Evaluate 4 a for a = 5 2/3 . express your answer in simplest form.

How many real and imaginary solutions does the equation x^2-3x=-2x-7 have?

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.