If a radioactive substance remains 80% of the initial amount then the half life of the radioactive substance is 2.5 years.
Given 80% of the initial amount of a radioactive substance remains.
If after 1 year the value or weight of the radioactive substance remains 80% means the rate of disappearing is 20% per annum.
If we clearly observe then it is forming a geometric progression and the rate is 80%.
Geometric progression will be if we assume the initial quantity be 100
is:
100,80,64,.........
we have to calculate the value of years in the value of term is 0.
the value of nth term of a geometric progression is
so,
r is 0.8
100*=0
=0
if we calculate this we will find n-1=11
n=12
So the full life of radioactive substance is 12 and the half life will be 6 years.
Learn more about geometric progression here brainly.com/question/12006112
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Answer:
Step-by-step explanation:
We need to find the LCM of 24, 72.
LCM
= Multiply all the factors
= 3 × 2 × 2 × 2 × 3
= 72.
Answer:
C. three; three
Step-by-step explanation:
Both an altitude and a median are a line segment with a vertex of the triangle on one end. There are 3 vertices in a triangle, so 3 altitudes and 3 medians.
<span><span>4<span>(<span>x−b</span>)</span></span>=x</span>Step 1: Add -x to both sides.<span><span><span><span>−<span>4b</span></span>+<span>4x</span></span>+<span>−x</span></span>=<span>x+<span>−x</span></span></span><span><span><span>−<span>4b</span></span>+<span>3x</span></span>=0</span>Step 2: Add 4b to both sides.<span><span><span><span>−<span>4b</span></span>+<span>3x</span></span>+<span>4b</span></span>=<span>0+<span>4b</span></span></span><span><span>3x</span>=<span>4b</span></span>Step 3: Divide both sides by 3.<span><span><span>3x/</span>3</span>=<span><span>4b/</span>3</span></span><span>x=<span><span>4/3</span>b</span></span>Answer:<span>x=<span><span>4/3</span><span>b</span></span></span>
Answer:
X²+y²+2x-10y+18=0 is the equation of circle
Step-by-step explanation:
Eqn of circle is: (x-h) ²+(y-k)²=r²
At (h, k) =(-1,5) and r=8 where h, k are center and r is radius.
Eqn is :(x+1)²+(y-5)²=8²
Or, x²+2x+1+y²-10y+25=8
Or, x²+y²+2x-10y+18=0 is the equation of circle