Answer:
It will take approximately 3.34 hours for the drug to decay to 90% of the original dosage
Step-by-step explanation:
As suggested, we use the formula for exponential decay:
From the given information, the half life of the drug in blood id 22 hours, so that means that it takes that number of hours to go from the initial value 
, to a final value equal to 
. Using this information we can find the decay rate "k" by solving for this parameter in the formula, and using the natural log function to bring the exponent down:
Now we use this value for the decay rate "k" to calculate how long it would take to decay to 90% of the original dose;
The answer is 14.3%
because if u times it by 7 u get 100 because there is 1/7 percent chance it it will be sunday then any other day of the week
32*1.2=38.4 (.2 is the 20%, and the 1 adds the percent to the original cost making it a mark up)
To find Ken's speed divide total distance by total time:
174 miles / 3 hours = 58 miles per hour.
In the equation for Brenda, the 57 is the miles per hour because you would multiply that by x ( hours) to get total miles (y).
Ken had the faster driving speed.
