In a school, three classes took the same examination.class A contained 30 pupils and the average mark for the class was 66.class B contained 22 pupils and the average mark for the class was 56.class C contained 20 pupils.The average obtained by all the pupils together was 1.5.calculate the average mark of class C.
A teacher gave a student the task of adding āNā natural numbers starting from 1. After a while, the student reported his result as 700. The teacher replied that his result was wrong. The student realized that
he had added one number twice by mistake. Find the sum of the digits of the number which the student had added twice.
In an examination,a student gets 5 marks for every right answer and loses 2 marks for every wrong answer.If he answers 50 questions and get 124 marks, how many are correct answers he attempted?