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:
5438.5
Step-by-step explanation:
To complete this equation, we must use the order of operations also known as PEMDAS.
For the case of this problem, we start by multiplying or dividing numbers before adding or subtracting numbers.
First let's start on the left:
100 x 54 + 77 ÷ 2
5,400 + 77 ÷ 2
5,400 + 38.5
5438.5
I hope this helps! Just remember to always add or subtract number last and start on the left, so that you don't get confused.
Unit price - price of one
0.95/5= 0.19p
hope this helps
