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
Answer:
She should earn 225 dollars.
Step-by-step explanation:
I know this because 50 ÷ 4 = 12.5 and 12.5 × 18 = 225.
You factor it. You can use the quadratic formula, completing the square, graphing, and the MATER P method
Answer:
1,000
Step-by-step explanation:
If your asking for the area you multiply 40 times 25
Answer:
97.94 is 83% of 118
Step-by-step explanation:
Let the missing number be x
97.94=83% of x
I.e, 97.94=83/100 × x
97.94=83x/100
Cross multipy 97.94/1=83x/100
We have, 97.94 × 100 = 83x × 1
9794=83x
Divide both sides by 83 to make x the subject of the formula.
9794/83=83x/83
118=x
