It would be 16 minutes because you would divide 80 by 20 and you get 4 so now you multiply 4 by 4 and you get 16
Answer: 
Step-by-step explanation:
Given
The surface area of a rectangular prism is 
Width of prism 
Length of prism 
height of prism 
Surface area is given by
![S.A.=2[lw+wh+hl]](https://tex.z-dn.net/?f=S.A.%3D2%5Blw%2Bwh%2Bhl%5D)
Put values
![34=2[2\times 1+1\times x+2x]\\17=2+3x\\15=3x\\x=5\ cm](https://tex.z-dn.net/?f=34%3D2%5B2%5Ctimes%201%2B1%5Ctimes%20x%2B2x%5D%5C%5C17%3D2%2B3x%5C%5C15%3D3x%5C%5Cx%3D5%5C%20cm)
Now, the volume of Prism is given by
Answer:
1,000.
Step-by-step explanation:
Answer: a - 4.512 hours
b - 1.94 hours
Step-by-step explanation:
Given,
a) A(t) = 10 (0.7)^t
To determine when 2mg is left in the body
We would have,
A(t) = 2, therefore
2 = 10(0.7)^t
0.7^t =2÷10
0.7^t = 0.2
Take the log of both sides,
Log (0.7)^t = log 0.2
t log 0.7 = log 0.2
t = log 0.2/ 0.7
t = 4.512 hours
Thus it will take 4.512 hours for 2mg to be left in the body.
b) Half life
Let A(t) = 1/2 A(0)
Thus,
1/2 A(0) = A(0)0.7^t
Divide both sides by A(0)
1/2 = 0.7^t
0.7^t = 0.5
Take log of both sides
Log 0.7^t = log 0.5
t log 0.7 = log 0.5
t = log 0.5/log 0.7
t = 1.94 hours
Therefore, the half life of the drug is 1.94 hours
