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;
Find a common denominator (12).
u/4=8/3
3u/12=32/12
Multiply each side by twelve to get rid of the denominator.
3u=32
u=1 2/3
1 and two-thirds equals 1.6666666 in decimal form, so the nearest tenth would be 1.7
<span>More please help me solve the problem
The stars have different brightness. The brightest stars are Grade 1 and the least degree luimnoase stars 6. The brightness of the stars shrinks 2.5 times with the passing from one grade to another. Whenever the stars are brighter Grade 1, Grade 6 than the stars?</span>
81000-37000=44000
Rounded to the nearest thousand
Answer:
90 g of water should be added and he will make 900 g of solution.
Step-by-step explanation:
Let x g be the amount of salt Ilya add to 810g of water to make 10% solution. Then 810+x g is the amount of new solution. Thus,
810+x - 100%,
x - 10%.
Mathematically,
So 90 g of water should be added and he will make 810+90=900 g of solution.
