Algebra
posted by ##000000 .
A cup of coffee contains about 100mg caffeine. The exponential function A(t)=100(0.84)^t is used to calculate the amount of caffeine in a body t hours after the coffee was consumed. Find the amount of caffeine in the body after 4 hours. Can someone help with a step by step break down?

yeah. plug in the value for t and use your calculator:
A(4) = 100(0.84)^4 = 100*0.5 = 50.0
Respond to this Question
Similar Questions

Math
When you drink a cup of coffee or a glass of cola, or when you eat a chocolate bar, the percent, P, of caffeine remaining in your bloodstream is related to the elapsed time, t, in hours, by t=5(logP/log0.5). a) how long will it take … 
Biochemistry
Hi, In this task for our school, we were requested to investigate a method for testing the amount of caffeine content in coffee. There are 3 main questions as fellows 1. What would be a good method to measure the amount of caffeine … 
statistics
The caffeine content of a cup of homebrewed coffee is a normally distributed random variable with a mean of 115 mg with a standard deviation of 20 mg. (a) What is the probability that a randomly chosen cup of homebrewed coffee will … 
Algebra
Hot Java Coffee Company adverties their decaffeinated coffee as 97% caffeine free as compared to their regular caffeinated coffee. If a cup of coffee is 8 ounces, how many ounces of decaffeinated coffee would you have to drink to get … 
Chemistry
Caffeine a stimulant found in coffee has the mass composition of C, 49.48%, H, 5.19%, N, 28.85%, O 16.48%. The molar mass of caffeine is 194.19g/mol. Find the molecular formula for caffeine. 
math
A cup of brewed tea has 54 milligrams less caffeine than a cup of brewed coffee. If a cup of tea has 66 milligrams of caffeine, how much caffeine is in a cup of coffee? 
science very urgent help?
Susan has heard that taking an overthecounter ‘energy’ pill, which contains as much caffeine as a strong cup of coffee, makes people feel alert and ‘speedy’. She wonders if taking this pill will make a difference to the reaction … 
Stats
Instructions for the Experiment / Data Collection regarding questions 14: Collect data regarding the caffeine content in a 16oz cup of coffee. Collect the amount of caffeine in 20 different brands of coffee. 1.Calculate the following … 
word problem urgent
The halflife caffeine in the human body is typically about 6 hours. If john drinks a large cafe mocha with an extra shot of expresso from a coffee shop at 8am (255mg caffeine), and then starts to feel drowsy around 4pm and drinks … 
Algebra
A is the amount of caffeine left in your body after two hours, C is the amount of caffeine originally ingested, and k is the halflife of caffeine (about 5.7 hours). Round all other numbers to the thousandths place. Formula A=C (0.5)2/k …