Question 949971
Ken deposits 6,000 into a saving account at t=0.
 The account pays simple interest at an annual rate 10%.
 Ken withdraws the entire balance of his savings account at t=12.
Find K's amt at t=12
k = 6000 + 6000*.1*12
k = $13,200
:
Steve deposits 12,000 into a saving account at a later date, t+x.
 Steve's account pays compound interest at an annual rate of 10%.
 Steve withdraws the entire balance of his savings account at t=12.
If Steve's account balance is twice that of Kevin's account balance at t=12.
 what is the value of x? (that is how long after t=0 did Steve make his deposit?)
{{{12000(1.10)^(12-x) = 26400}}}
{{{1.10^(12-x) = 26400/12000}}}
{{{(1.10)^(12-x) = 2.2}}}
(12-x)log(1.1) = log(2.2)
12-x = {{{log(2.2)/log(1.1)}}}
12 - x = 8.2725
-x = 8.2725 - 12
-x = -3.727
x = 3.727 yrs after Ken's deposit which was t=0
:
:
We can check this. Steve's 12000 was in the bank 8.2725 yrs
12000(1.1^8.2725) = 26400