Answer:
I believe that is 24
Step-by-step explanation:
To understand this question, we need some knowledge on radioactive decay. This type of nuclear decay is called a beta decay
<h3>Beta Decay</h3>
This is the process where a radioactive material is fired or naturally emits a beta particle which is equivalent to the lose of an electron and spontaneously becomes an entirely different element.

The participating actors in this nuclear reaction are
This is the decay process of helium particle in which it became a lithium particle and emitted an electron in the process.
Learn more on beta decay here;
brainly.com/question/9615302
#SPJ4
Answer:
20,000
Step-by-step explanation:3 days= 5000 so each 3 days 5000 burns down for 12 days so 5000 x 4
Tan Ф= opposite side / adjacent side
Data:
adjacent side=15
Ф=30º
so:
tan 30º=x/15
x=15(tan 30º)
x=15(1/2)
x=7.5
Answer: x=7.5