In the following question, some part of the sentence may have errors. Find out which part of the sentence has an error and select the appropriate option. If a sentence is free from error, select 'No error'. The reason for (1)/ his failure is because (2)/ he didn't study at all. (3)/ No Error (4)
Irfaan loves black coffee. A roadside stall selling a cup of black coffee at Rs. 120, offered 25% discount to Irfaan. If Irfaan was willing to pay even Rs. 200 for this cup of black coffee, Irfaan's consumer surplus is