Compound Interest Question...

[Elena_W]

I needed help solving this, A financial obligation requires the payment of $500 in 9 months, $700 in fifteen months, and $600 in 27 months. When can the obligations be discharged by a single payment of $1600 if interest is 10% compounded quarterly? (Let the focal date be now.)

[MallyJ]

Someone has already answered this question on your previous post ..... at length by the look of it. What was wrong with that answer?

[Elena_W]

I couldn't understand the method of it, so i decided to repost to see if anyone else would know how to do it.

[MallyJ]

You might not!!

[Jonathan-Joe]

Elena, if you had acknowledged my effort on the original post but said you didn't understand it, I would have tried to make it clearer. Actually, I now think it would be better to work back from the $600 payment.
I'll give you some guidance but not a complete answer.
If $600 discharged the debt at 27 months, how much was owed after the $700 repayment 12 months earlier? (that is with 4 quarters interest).
So how much before the $700 was paid?
Use the same thinking to work out amounts owing after / before the other two repayments to find the original debt. Then find how long this amount will increase to $1600 at the given interest rate.

[Elena_W]

I really did appreciate your help, but didn't want to bother you by asking for a clarification. I'm sorry if I offended you, and once again I really do appreciate your help. Thanks so much for your time!