Answer:
14,250 years old.
Step-by-step explanation:
First, multiply the two lifetimes. - 11,400.
Then, divide 5,700 in half for the 0.5 lifetime. - 2,850.
Lastly, add them all up. - 11,400 + 2,850 = 14,250 years old.
sorry if incorrect <3
thats what i understood XD