Answer:
0.0001075
Step-by-step explanation:
The relation between halflife and rate at which it is decaying is given by

now in the above problem halflife is given as 2800 years substituting in the above equation we get the value of rate at which it is decaying to be rate=0.0001075.
Answer:

Step-by-step explanation:
The area of the circumference of a circle is:

We know that r is 8, so we can plug that into the formula.
However, there's a problem. We only want 3pi/4 of the circumference, not the entire circle's circumference. Therefore, we have to divide by part/whole. In this case, the part is 3pi/4, and the whole is 2pi (the entire circle is 2pi radians).

Answer:
Therefore 70 year Marc's grandmother be 5 times of as Marc will be after (70-56) = 14 year.
Step-by-step explanation:
Given, Marc was born on his grandmother's 56th birthday.
Let , x year will Marc's grandmother be 5 times as Marc will be then.
At that time the age of Marc will be = (x-56) year
According to the problem,
x= 5(x-56)
⇔x = 5x - 280
⇔x-5x= -280
⇔-4x=-280
⇔x=70
Therefore 70 year Marc's grandmother be 5 times of as Marc will be after (70-56) = 14 year.
I think the correct answer is 250 because 375 divided by 1 and a half is 250. Hope this helps. Brainliest??