Answer:
2,674.14 g
Step-by-step explanation:
Recall that the formula for radioactive decay is
N = N₀ e^(-λt)
where,
N is the amount left at time t
N₀ is the initial amount when t=0, (given as 42,784 g)
λ = coefficient of radioactive decay
= 0.693 ÷ Half Life
= 0.693 ÷ 18
= 0.0385
t = time elapsed (given as 72 years)
e = exponential constant ( approx 2.7183)
If we substitute these into our equation:
N = N₀ e^(-λt)
= (42,787) (2.7183)^[(-0.0385)(72)]
= (42,787) (2.7183)^(-2.7726)
= (42,787) (0.0625)
= 2,674.14 g
Ok so the wording is confusing
is it
A. 3 friends took 1 slice each (total is 3 slice) or
B. 3 friends took 1 slice total
if A, go to AAAAAA
if B. to to BBBBB
AAAAAAAAAA
3 slices taken
fraction is parts out of whole
what is left
left=original-taken
taken=3
original=8
8-3=5
5=left
fraction is 5/total=5/8
BBBBBB
taken=1
fraction is parts out of whole
what is left
left=original-taken
taken=1
original=8
8-1=7
7=left
fraction is 7/total=7/8
if 3 slices taken total then 5/8 left
if 1 slice taken totl then 7/8 left
The answer is X=23 and y=9
A quantity in a standard time or period maybe lol
Answer and workings are in the attachments below.