This is one part of a problem question:
R had promised his friends S, T, and U to sponsor their participation in a Lands End to John O'Groats bicycle ride in aid of the Contracts Lecturer's Benevolent Fund. S lacked the funds to buy a suitable bicycle so R lent him £600 on terms that S would repay him at the rate of £100/month after the sponsored ride had been completed. Six months later, S was 3 months in arrears with his payments and told R that he had lost his job and could only pay £50/month for the time being. R agreed to accept £50 per month but after S had made two payments R heard that had won a large sum in a lottery. R wished to claim the balance of the sum still owing immediately.
...or just paranoid?