The original number would be 900
Answer:
0.318
Step-by-step explanation:
222 ..........................................
7978 years
Step-by-step explanation:
A = A02^(-t/hl)
where hl = half-life.
Dividing both sides by A0 and taking the logarithm, we get
ln(A/A0) = -(t/hl)ln2
or solving for t,
t= -(hl)ln(A/A0)/ln2
note that A/A0 = 0.38
t = -(5715 yrs)[ln(0.38)/ln2]
= 7978 years
12000 - 2900 = 9100
9100 / 36 = 252.77.....about 253 per month
