If 
is the amount of strontium-90 present in the area in year 
, and it decays at a rate of 2.5% per year, then
Let 
be the starting amount immediately after the nuclear reactor explodes. Then
or simply
So that after 50 years, the amount of strontium-90 that remains is approximately
or about 28% of the original amount.
We can confirm this another way; recall the exponential decay formula,
where is measured in years. We're told that 2.5% of the starting amount 
decays after 1 year, so that
Then after 50 years, we have
Usually you are given more information about the rectangle such as distance of length in terms of width.
You know that the formula for perimeter is
P=2(l+w)
Substitute p and the other values to find width.
Hope I helped :)
Answer:
a = 4
Step-by-step explanation:
Here, we want to write and solve the given equation
a - 2.5 = 1.5
a = 2.5 + 1.5
a = 4
To check, we simply substitute a = 4
That would be;
4-2.5 = 1.5
This is correct
Answer:
5/12
7/12
125/36 = 3,47%
50/11 = 4,54%
Step-by-step explanation:
Probability a black sock is selected when a person chooses 1 sock = 5/12
Probability a white or brown sock is selected when a person chooses 1 sock =
7/12
Probability a person chooses 3 socks and selects a white first, a black second, and a brown last if the socks are replace = (4/12 * 5/12 * 3/12)*100 =125/36 = 3,47%
Pobability a person chooses 3 socks and selects a white first, a black second, and a brown last if the socks are NOT replace = (4/12 * 5/11 * 3/ 10)*100 = 50/11 = 4,54%
M=p=x
x/45=16/x
x^2=720
x=sqrt(720)
sqrt mean root
m= sqrt(720)
