Answer:you would have saved $31 after 5 days
Step-by-step explanation:
You double the number of dollars in the envelopes from the day before. This means the amount in a day is double the amount in the previous day. Therefore, amount of money in the envelope is increasing in geometric progression. The formula for determining the sum of n terms of a geometric sequence is expressed as
Sn = a(r^n - 1)/r - 1
Where
a represents the first term.
r represents the common ratio.
From the information given,
a = 1
r = 2
n = 5 days
S5 = 1(2^5 - 1)/2 - 1
S5 = 32 - 1 = 31
Answer:
yessssss
Step-by-step explanation:
Answer: in explination
Step-by-step explanation:
annual interest = .05(4000) = 200
to double, you need another $4000
number of years = 4000/200 = 20
annual interest = .05(4000) = 200
to double, you need another $4000
number of years = 4000/200 = 20
it will take 20 years
to check if you are right you would...
Check:
simple interest on $4000 for 20 years at 5%
= .05(20)(4000) = 4000
the amount = what we had + new amount
= 4000 + 4000 = 8000 which is double what we started with
So the answer would be it took 20 years.
