Doug because his sequence follows a rule of multiplying by -1/2
Hope I got it right for your sake.
9514 1404 393
Answer:
3/10
Step-by-step explanation:
(3/8)/(1 1/4) = (3/8)/(5/4) = (3/8)/(10/8) = 3/10
Answer:
12.5
Step-by-step explanation:
37.50÷15=2.5
2.5×5=12.5
Answer:
A) 277 million years
Step-by-step explanation:
Here, decay of U-238 is first order reaction. (since most of the nuclear decays are first order).
so, the equation t =
× ln(
)
where, t = time from start of reaction
k = reaction constant
A(0) = initial concentration; A = present concentration.
⇒ 4.5 billion = 4500 million years =
× ln2.
Now, given 95.82% of parent U-238 isotope is left.
⇒ t =
× ln(
)
t =
× ln(
)
⇒ t ≅ 277 million years.