Answer:
is the common ratio
Step-by-step explanation:
Common ratio(r) states that the ratio of each term of a geometric sequence to the term preceding it.

Given the sequence:
225, 45, 9, .........
Here,


and so on...
Using definition to find r.

After solving we get;

Therefore, the common ratio is, 
Answer:
12%
Step-by-step explanation:
calculator
B because if the circle has a radius of x2 the 1/2 of that would be a+c bringing in c to become abc or a+b+c
6x - 4(x + 3)
6x -4x -12. Distribute
2x - 12. Combine like terms
The "k" value should have units and should be negative.
k = -.07 / seconds
Half-Life = ln (.5) / k
Half-Life = ln (.5) / -.07
Half-Life = -.693147 / -.07
Half-Life = 9.9 seconds
(actually, wkpedia says half-life of Krypton 91 is 8.57 seconds)
elapsed time = half-life * log (bgng amt / end amt) / log (2)
elapsed time = 9.9 * log (100 / 10) / 0.30102999566
elapsed time = 9.9 * 1 / 0.30102999566
<span><span>elapsed time = 9.9 * 3.3219280949
</span>
</span><span><span><span>elapsed time = 32.8870881395
</span>
</span>
</span>
<span>elapsed time = 32.89 seconds (rounded)
Source:
http://www.1728.org/halflife.htm
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