Question

Brandon and Zach each have $600 to invest. Brandon’s investments earn a rate of 10.5%, and Zach’s investments earn a rate of 6.5%. Both are compounded continuously. Approximately, how much more money will Brandon have than Zach when Zach’s investments are worth $900?

$255
$241
$184
$264

Answer 1

A=pe^rt
First find the time for zack's investment
T=(log (A/p)÷log (e))÷r
A 900
P 600
R 0.065
T=(log(900÷600)÷log(e))÷0.065
T=6.24 years

Now find the difference between the investments
600×e^(0.105×6.24)−600×e^(0.065×6.24)=255

So the answer is a