Answer:
D. About 800 years
Step-by-step explanation:
Use the half-life equation:
A = A₀ (½)ⁿ
where A is the final amount,
A₀ is the initial amount,
and n is the number of half-lives.
0.90A₀ = A₀ (½)ⁿ
0.90 = (½)ⁿ
To solve for n, take log of both sides:
log 0.9 = n log 0.5
n = (log 0.9) / (log 0.5)
n = 0.152
It takes 0.152 half-lives. The half-life of carbon-14 is 5730 years.
0.152 × 5730 years = 871 years
The closest answer is D.
Answer:
We can use quadratic formula
a=3, b= -1, c=4
Step-by-step explanation:
Answer: Sally walked 3 minutes faster per mile
Hope it helped!
ANSWER

EXPLANATION
From the given information, Elena chooses a number from 1 to 10.
The sample space is
S={1,2,3,4,5,6,7,8,9,10}
n(S)=10
The numbers greater than 5 are:
E={6,7,8,9,10}
n(E)=5
The probability that, she chooses a number greater than 5 is:

Substitute the values,


Fraction: 1/512
decimal: 0.001953