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:
90000
Step-by-step explanation:
To get the total area multiply 75 by 30 then to get the number of people multiply the product by 40. 75*30*40=90000
Because 3/6 is equal to 1/2.
You multiply the 1 (in 1/2) by 3, and the 2 (in 1/2) by 3 to get 3/6. You need to have a common denominator, and 6 was the common denominator.
Answer:
dimension is 5cm * 4 cm
Step-by-step explanation:
As the plane is parallel to the base, the ratio between plane's length and width is equal to the ratio of that of the base. -> similar shape.
Moreover, it also divided the rectangular prism into 2 smaller rectangular prism. hence the plane is identical to the base. Hence, same dimension.
see photo