Working out lost interest

[DCS]

How would someone work out what interest would have been earned on R150k if it was sitting in a normal 32 day savings account over a 2 year period?

Not sure the interest rate to use (would 7% be about an average amount)?

Long story short my folks borrowed me money (not expecting interest), but wanna work out what they lost out on to pay that back...

 

[requiem]

It is fairly easy

If you take R150k at 7% per year.

That gives R10500 a year in interest.

If you wish to compound the monthly interest and charge interest on that it gets a bit more complicated.

 

[Jehosefat]

If you want to do monthly compounding the interest calc is: I = 150,000*(1 + 0.07/12)^24 -150,000 = R22,470.90

 

[Polly101]

*lent not borrowed

 

[TheChamp]

How would someone work out what interest would have been earned on R150k if it was sitting in a normal 32 day savings account over a 2 year period?

Not sure the interest rate to use (would 7% be about an average amount)?

Long story short my folks borrowed me money (not expecting interest), but wanna work out what they lost out on to pay that back...

Good on you man, pay back the money.