math(simple interest)
posted by Sat on .
Suppose that the current rates on 60 and 120day GICs(Guaranteed Investment Certificates) are 5.50% and 5.75%, respectively. An investor is weighing the alternatives of purchasing a 120day GIC versus purchasing a 60day GIC and then reinvesting its maturity value in a second 60day GIC. What would the interest rate on 60day GICs have to b 60 days from now for the investor to end up in the same financial position with either alternative?

Since they are short term instruments, they pay simple interest.
$1000 invested in a 120 day GIC collects insterest of the amount
I1=1000*0.0575*120/365=$18.90411
$1000 invested in a 60 day GIC collects interest
I2=1000*0.0550*60/365=$9.041096
Therefore the amount needed for the next 60 days
= $18.90411  $9.041096
= $9.86301
Effective interest rate
= 9.86301/60*365/1000
= 0.06
It will require 6% interest for the GIC for the next 60 days to catch up with the equivalent of the 120day GIC.