The answer is 28 years
At = A0 * e^(-k * t)
At = 12 g
A0 = 15 g
k = 7.9 × 10^-3 = 0.0079
t = ?
12 = 15 * e^(-0.0079 * t)
12/15 = e^(-0.0079 * t)
0.8 = e^(-0.0079 * t)
Logarithm both sides (because ln(e) = 1:
ln(0.8) = ln(e^(-0.0079 * t))
ln(0.8) = (-0.0079 * t) * ln(e)
-0.223 = -0.0079 * t
t = -0.223 / -0.0079
t = 28.23
t ≈ 28 years
Answer:
5
Step-by-step explanation:
Using the Pythagorean theorem:
a^2 + b^2 = c^2
3^2 + 4^2 = c^2
9 + 16 = c^2
c^2 = 25
c = 5
-0.83 because that's the way to go
Probability of heads or tails is .5
so you do (.5)^3 and you get D = 0.125
Answer:
They will save $90 each month
Step-by-step explanation:
300*30%
or
300*.3
90