Answer: 0.87400mg of caffeine.
Step-by-step explanation:
You have
N(t)=N0(e^−rt)(1)
as a general Exponential decay equation where N0 is the amount at t=0, N(t) is the amount remaining at time t and r is the exponential decay constant. You're specifically given that after 10 hours, the decay factor is 0.2601, i.e.,
N(10)/N(0)=N0(e^−10r)/N0(e^0)= e^−10r=0.2601 . .(2)
Taking the last 2 parts of (2) to the power of 0.1t gives
e^−rt=0.2601^.1t . .(3)
This means that
N(t)=N0(e^−rt)=N0(0.2601^.1t). .(4)
Also,
N(2.56)N(1.56)=N0(0.2601.1(2.56))N0(0.2601.1(1.56))=0.2601.1(2.56−1.56)=0.2601^.1
= 0.87400mg of caffeine.
Answer:
2998 ; 17%
Step-by-step explanation:
Given the function:
t(c)=-3970.9(ln c)
c = % of carbon remaining ; t = time
1.) c = 47% = 47/100 = 0.47
t(0.47) = - 3970.9(In 0.47)
t = - 3970.9 * −0.755022
t = 2998.119
t = 2998
B.)
t = 7000
t(c)=-3970.9(ln c)
7000 = - 3970.9(In c)
7000 / - 3970.9 = In c
−1.762824 = In c
c = exp(−1.762824)
c = 0.1715596
c = 0.1715596 * 100%
c = 17.156% ; c = 17%
Answer:
-1/3
Step-by-step explanation:
The common difference is how much it goes up by with each new number, so you can see that each time it goes down by 1/3. This means that the common difference is -1/3.
This would equal about 23,900
i hope this helps you.
Answer: it will take 5 months for both gyms to cost the same.
Step-by-step explanation:
Let x represent the number of months for which the total cost of gyms are the same.
Gym A charges a new member fee of $65 and $20 per month. This means that the cost of using gym A for x months would be
20x + 65
Gym B charges a new member fee of $25 and $35 per month but you get a discount of 20% monthly.
20% of 35 is 20/100 × 35 = 7
The monthly charge would be
35 - 7 = 28
This means that the cost of using gym A for x months would be
28x + 25
The number of months that it will take for the cost of both gyms to be the same would be
20x + 65 = 28x + 25
28x - 20x = 65 - 25
8x = 40
x = 40/8 = 5
