Answer: She started with $160.
It will take 6 weeks before she has less than half of what she originally invested.
Step-by-step explanation:
If her money is decreasing in value by 11% each week, it means that the rate at which it is decreasing is exponential.
We would apply the formula for exponential decay which is expressed as
A = P(1 - r)^t
Where
A represents the value of the investment after t weeks.
t represents the number of weeks.
P represents the initial value of the investment.
r represents rate of depreciation.
From the information given,
A = $142.40
r = 11% = 11/100 = 0.11
t = 1
Therefore
142.40 = P(1 - 0.11)^1
142.40 = P(0.89)
P = 142.4/0.89
P = 160
For her to have half of what she invested originally, then
80 = 160(0.89)^t
80/160 = (0.89)^t
0.5 = (0.89)^t
Taking log of both sides to base 10
Log 0.5 = log0.89^t = tlog0.89
- 0.3010 = - 0.051t
t = - 0.3010/- 0.051
t = 5.9
Approximately 6 weeks
Factor the Polynomial by solving x^2 + bx + c = 0.
m^2 - mv - 56v^2
Factor by grouping.
(m−8v)(m+7v).
x^2 + bx + c = 0
Answer:
x = 69.44
Step-by-step explanation:
We have, 36% × x = 25
or, 36/100 × x = 25
Multiplying both sides by 100 and dividing both sides by 36,
we have x = 25 × 100/36
x = 69.44
If you are using a calculator, simply enter 25×100÷36, which will give you the answer.
Answer:
Step-by-step explanation:
Use the formula for volume of a cone
V = 1/3 pi r^2 (h)
V = 1/3 pi 66^2 (18)
V= 1/3 pi 4356(18)
V = 1/3 pi 78408
V = 1/3 264,201.12
V = 82,067.04cm^3
