Answer:
B
Step-by-step explanation:
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:
60,120,180
Step-by-step explanation:
360:(2+4+6)=30
30×2=60
30×4=120
30×6=180
His brothers have 4 games
He had 10 games
So in total there are 14 games
And if there are 2 cases and each one had the same amount, then in each one there would be 14÷2=7
In each case, there are 7 games.
