Given :- The average marks of Ravi in five subjects are 150 In mathematics 43 was misread as 23 Concept :- Average = (Sum of total numbers)/Total number Error's in marks = Original marks - Wrong marks Calculation :- ⇒ 150 = (Sum of all subject)/5 ⇒ Sum of all subject =150×5 ⇒ Sum of all subject =750 Now, ⇒ Error's in marks =43−23 ⇒ Error's in marks =20 Now, this 20 marks must be added in sum of marks ⇒ New sum of marks =750+20=770 ⇒ New average =(770/5) ⇒ New average = 154 ∴ Correct average = 154