Case study
Sophia has been struggling to pay her rent recently so she borrowed £1000 from her friend Imran. She has promised to pay back the whole amount on 20 February.
On 18 February, Sophia warned Imran that she could not pay back £1000 on the day the payment was due. Imran said he was happy to accept £600 in satisfaction of the whole debt if she paid him on 18 February. Three weeks later Imran demands the payment of the remaining £400.
Advise Sophia whether she has to pay back the remaining sum of £400 to Imran.