Answer:
15
integers from 1 to 9 have only one number each, so in total 9 numbers. integers from 10 to 12 have 2 numbers each, 3*2=6. 9+6=15
Answer:
16.4
Step-by-step explanation:
If it is asking for the tenth it will be the 1st one after the point and you round it to the next one.
The percentage of the radioactive isotope left is 25.0000%.
<h3>What is the half life?</h3>
The half life of a radioactive isotope is the time that will elapse before only half of the number of original isotopes will remain.
Now;
We are told that;
Half life (t1/2) = 55 days
Time taken (t) = 115 days
Ratio of isotope remaining = N/No
Thus;
N/No = (1/2)^t/t1/2
N/No = (1/2)^115/55
N/No = (1/2)^2
N/No =1/4
Hence, the percentage = 1/4 * 100/1 = 25.0000%
Learn more about half life of an isotope:brainly.com/question/16387602
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Answer:
Step-by-step explanation:
