Answer:
4
Step-by-step explanation:
Answer: 1/18
Step-by-step explanation:
9 total marbles
2 red
so the first time he picks it would be a 2/9 chance of the marble being red
the second time there would be 8 total marbles and 2 red, so it would be a 2/8 or 1/4 chance.
the probability is found by doing 2/9*1/4 which equals 2/36 or 1/18.
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
Step-by-step explanation:
The new price of the flash drive is not $10 because 20% of $10 is 2 and if 2 is marked down by 10% it would not be $10.
