Answer:
the 13th one is 115
Step-by-step explanation:
So 25%=1/4 so technically you just do 5 times 4 since you need 4 more to have a full 4/4 or full 100% so 5 times 4 is 20 so there are 20 totals toys in the bag
Answer: 18
Step-by-step explanation: Simplify 2^3 to 8. 3/4 (8+4^2). Simplify 4^2 to 16. 3/4 (8+16). Simplify 8+10 to 24. 3/4*24. Use this rule: a/b * c = ac/b. Simplify 3*24 to 72. 72/4.
<em>Hope this helps!</em>
10. B
11. D
12. C
13. B
14. B
15. D
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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