Revenue Recognition

I had a question regarding credit sales, my tutor gave me an example that a Mr.c made a transaction of £50,000 with Mr.A which Mr.A will pay back after 2 years, The goods are delivered and dispatched , the tutor said in the current year he will record £40,000(net present value cost of capital 10%) and record remaining amount £10,000 as £5000 for next two year as interest income, now my question is that is this correct? And if it is correct then is that £5000 like a deferred income? Regards