I cant see it :/ !!!!!!!!!!!!!!!!!!!!!
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;

Answer:
420 points
Step-by-step explanation:
multiply 7 by 60
Answer:
The total length of the pathway now is 1,541 ft
Step-by-step explanation:
To calculate the length of the pathway now, what we need to do is to have a consistency in units.
Thus, we need to convert the 513 yards to ft
Mathematically 1 yard = 3 feet
Thus 513 yards will be = 513 * 3 = 1,539 ft
Thus the total length of the pathway now will be 1539 ft + 2 ft = 1541 ft